So, a similar system (not the same mind you) was in eq for a very long time so ive come across pretty much every conceivable question about vets before.
what a lot of people say is: its dumb i dont like it! -this is perfectly fine, the way to make them happy is to keep the old system
Assuming you like the new system or have issues with the old one, the next thing to address is why we even want to change anything. So usually the complaint is something along the lines of "experimentalllls" which is a perfectly valid complaint imo, its fairly unintuitive that exps should target engies for best vet, and then a 5% ML walks out of an enemy base on 80% hp. But the important part is, that the CHANGE that the new vet system does in this case, is remove the vetting up process. so the issue was not how or when a unit got vet, it was just that it did. an interesting observation.
If we look at the typical unit, we notice that before in 90% of cases, it died before it got any vet. There were no complaints about vet on the typical unit. They didn't get vet and no one really minded.
Actually thats not quite true. There were some complaints, but they were that some units got it too fast! Way back in 2013 percy and other vets were nerfed so they got it ~2x slower. Again a very similar situation to the complaint with exps. Again solved in to the same effect. And coupled with the bit that no one thinks of regular units getting vet, its adding to the above conclusion:
No vet, no problem.
So, historically we can see that pretty much all complaints and cases arose from when a unit got some vet. Of course there are lots of other things one could say at this point, that the real issue was the nature of the vet system, such as the insta heals, or that it should be lower values but happen more frequently, and a whole myriad of other potential solutions.
Indeed, thats usually what people say after hearing the above, that just something else is wrong but vet is still a great idea if done right. Indeed thats what me and Ithilis used to think a couple of years back when EQ was still young. So we explored this. Quite a lot. There was everything, ranging from delayed instaheals to reduced ones, to more max hp and regen to compensate, units vetting up at 100% of their cost or faster, a whole range of stuff was tried.
Long story short, here are the conclusions:
-The mechanism of the vet doesnt really matter, as long as the actual vetting process gives an advantage during combat, it leads to the same issues. Or worse depending on the frequency/"OPness" of the vetting. If a unit gets instahealed it leads to complaints, if it gets a great regen boost, it leads to complaints, if it gets huge max hp it leads to complaints. If you want i can give actual quotes for each of those xD
-Reducing the magnitude to find some "happy medium" just leads to the exact same issues, but either less frequently or less intensely. Its totally possible and even easy to find a solution which is tolerable, but its simply wrong to call it good. The old vet system is perfectly tolerable. We have been playing with it for years.
-Likewise, if after the process, the unit in question is stronger than an unvetted version of itself, this leads to complaints. Its almost the same as above but theres a slight distinction since if it doesnt lead to issues that second it can lead to issues later. This is more the regen+ large max hp approach. That didnt work either.
Now, this makes people unhappy because it makes a players expectations not be met: when an ML walks into a base and leaves it with more than it came, or you spend in a strat to finish it off and then its suddenly 50% hp and not 5%, it makes you upset. Thats perfectly normal, it happens in life overall. Theres papers published about this, design principles based on this, its a part of what makes people people i guess.
And thats just what vet does. It messes with your expectations. Supcom is where you look at the map, see things and then make predictions on whats going to happen. You see 20 tanks and you know that your 30 tanks can kill them, so you attack and take over mex spots or w.e. However, if the enemy army is vetted, its no longer the case. your predictions become less accurate. The outcome of the game becomes more "random" and less based on skill (not actually true but thats the perception)
So, where can vet go? really? well it may seem like I'm a total vet hater, but that's not quite the case. Here are some possible avenues:
-The fuel direction. When was the last time you cared about fuel? never probably. its effectively been removed. Doing this to vet would make it mostly a pretty number. Its actually a pretty small change. Regular units never got vet. The only things to address are exps and acus. Exps can get their vet effectively removed so people will try to use an exp to kill things and not to search for engies. Acus are a special case here since they are a one of a kind unit and it would be cool if they can stay, but they dont really NEED it either. This is effectively solving the issue by making it irrelevant. Its mostly the path we are on now.
-TVG - the other extreme, make vet a core system that everyone expects. Not just a useful side thing that messes with your expectations. Change it enough that you get different expectations from the game. This would lead to some interesting gameplay where your strats would revolve around picking a unit type to abuse and going with that, rather than things like t3 rush or w.e.
-A different system that benefits your units not by making them better but by restoring them to their original state. This ones a little hard to explain, but from what a lot of people say, this is what they really want without realizing it. Its a system where after getting vet your unit becomes useful again, but doesn't mean that it can beat 2 of itself. This is actually a little hard to pull off without just running into the age old issues described above. Either a mix between not being useful and adding a regen amount that repairs your unit but not enough to act like nano, or some special scripted code that only regens out of combat and such. Interestingly, this is actually by far the hardest to achieve, properly. This was explored in EQ as well, but we kept running into the same issues as with an "op" vet system. There is actually a better solution though. Usually what people want is to fight, go back and recieve a fresh new unit, thus rewarding caring for your units. This is a bit of an ironic view (caring for your units is already extremely important, see: mass donations and how it loses you games) but it does work in other games. The way they do it though, is using a repair system. At a glance it can be very similar to a vet system (kill stuff, wait, your units are max HP again) but the key difference here is a need for infrastructure. Doing this in supcom would likely require either absurd code or a new unit type - some land staging facility. Anyway, this post has gone on for far enough, and a working repair system is a whole new topic.
TLDR: people say they want more vet but they also say the dont like vet so they need to work out what they want first. Thanks.