Not like Unit drops, not like Field Promotion or any of that drop crap like legit Micro try to keep your units alive?
For example I didn't realize the Spartan units Veterancy can actually go over 3 in a vehicle. That's a pretty good call back to Halo Wars 1. Which reminds me what is the highest level in the game it can't clearly be 3 anymore?
Final question what is your favorite veteran unit. Mine had to be getting a 2 star Colossus. No seriously try leveling that thing up and you see why I'm so proud.
i keep my units alive from start to finish. if my units die i feel guilty and like im losing the war. so like... even suicide grunts i'll only explode 2/3'rds of the unit and then heal them with engineers if i can. it's hard to do so i rarely ever build suicide grunts or throwaway units. the less you lose in a fight the more you win. of course eradication and such things are a bit too common to go an entire game without losing 20 or so units. i just make sure that if i lose a unit that it definitely was worth it.
i've had veterancy 3 marines before. the more hp and damage a unit has the more the veterancy is worth getting, but everything benefits from it to some extent. marines for example seem to heal quicker (though there is a healing bug that can happen)
my guess is that veterancy is unlimited just like how it is unlimited in blitz, but since you have to earn it by killing units games probably never last long enough to earn it.
it's amusing because i'll be sitting at my base just scouting and fortifying in a 3v3 and the rest of my team is groaning because im "not doing anything" when in reality my army has already been built and im just stacking veterancy where i can without over committing myself.
while it's true that the bigger army usually wins it's also true that if you run your army around in a huge group that your opponents can just 1shot them with their ultimate. i tend to build a few of each unit and set them up into 4 squads so that i can deal with situations as needed. backbone units will be my armies core and then i'll have anti ___ and anti ___ to cover a retreat.
6 or so marines + a scorpion here. 2-3 cobras with nightingales and 1 or 2 wolverines there. a sniper in the garrison near my base. etc. much much easier to cycle between things when you dont have to deal with 50 or 60 different units.