Made you care most for your units ?

I'll kick of with :

Fantasy General

Dominions 5

Rules all be all the game you never play anything other.
and no that's not a overstatement.
also a fun fact is that the Lore is based on real human lore for example Mictlan (demon macaw) or machaka (african gods) lion warriors for example.
the game can teach you a lot about other religions and lore based on faith and forgotten tails
https://www.youtube.com/watch?v=FP6zxwCCCDc

over 5000 Units no shit the manual is 389 pages thick

Panzer corps on ironman. But making sacrifices for a major victory is rather the point.

ah yea ... iron man games, i'm currently in my 5th try for the fantasy general 2 long campaign, every time some dufus mistake or impossible aimed levels, it becomes even worse when you see many reviewers noting how savescumming actually felt like a must .... iron man tactical games do indeed seem to go with the necessary amount of dread concerning loss over your units but it is not like those couple of veteran units in fantasy general that you name at a certain point, adres a certain role too, think about the magical artifact the unit should carry... weeping over lost experience remains the same thou

I dont like loadspamming , imho that just removes the actual feat of winning.

Dito.
UFO Defense before that.

Also, Battle Brothers and Darkest Dungeon.

Getting too attached to the heroes in DD is really a mistake ;-)

Warhammer 40.000: Chaos Gate. You have to make it till the end with the men you're assigned at the start; there's no way to acquire new troops. Every soldier is precious.
Also: Incubation, for pretty much the same reason. You can recruit new soldiers, but it's not always practical, and in the later stages of the game, you're really gonna need your veterans.

ah yea, incubation, had a lot of fun with that one as my younger self, these days i can't even get past mission 3 i belief ( but someday i will try!!! )

Well I mostly care the same for them , when they die reload gonna happen :D
Most games are designed to keep your champs as they get more and more experienced and losing them is more or less game over.

I don't like it when games have mechanics like permadeath or random non-respawning treasures that encourage that sort of thing. I also don't like it when games try to prevent that sort of approach; in other words, games should not mess with the save system in the name of challenge. I am of the opinion that no game should ever put a player in a worse position at the end of a playing session than at the start. (The worst I consider acceptable is being only able to save at save points, provided that said save points aren't too far apart.)

As for the original question, I would say that SRPGs are more likely to make me care for individual units than pure strategy games, as in SRPGs you get to see your units grow and develop over a series of battles. (Then again, I'm not adverse to using strategies like Fell Seal's Rapturous Chant (kills caster, heals all allies, this death doesn't cause injury) followed by Revive.)

Why not just revive them (or have them be automatically revived by the battle ending)?

Dunno ask the developers why it is not in their games , i like when team members review after the battle.

Xenonauts when I tried Ironman.

Also Jagged Alliance 2, where even though by comparison with XCom ironman is completely beyond me and I always loaded a save if a merc got killed, you still wind up caring a lot for the mercs because of how much personality they have. E.g. "Oh no Steroid's down! Medic!!"

Hello Zimerius!

For me it is an easy answer: "Warhammer Dark Omen"!
First, it really made a difference which decisions you chose, both in what type of units you could add to your bands, as well as when you arrived on the battlefields, having either to defend a position or take it back from the enemies who already invaded the place. Also the visual and audio feedback from the units during gameplay helped a lot to get attached and feel for each and every loss.

On a close second I would call "Ground Control" (the original), because their were almost no reinforcements, you simply had to do your best to keep them alive.

Kind regards,
foxgog