Update:
I think I was overrelying on snipers (I liked to bring two). Which did give a bonus of sorts insofar you had LESS units under fire.... but it also led to fire being spread amid less units. Often led to wounded snipers, too, because of having to put them in the line of fire. A few missions in which I had to bring just one sniper because the other ones were wounded, I've found that playing it safe + close support yields me better results than having two snipers instead of one, in general.
Besides, one of the reasons I liked two snipers was because a ghosted ranger made them uber at taking potshots at enemies without revealing your real position (I've managed to do very good black site runs with that strategy). But with a bit more patience you can do that with just one sniper. And if your ranger gets unghosted, well, you'll get more benefits from having more close support units.
I think my overreliance on snipers was a leftover from XCOM2012, in which snipers were simply *the* way to go. Although, TBH, since sniper-scout couples were a standard in OldCOM, it might be a leftover from there as well.
OldCOM and NewCOM are not really interchangeable tactics-wise because there are huge gameplay differences between the two. Not necessarily making either better or worse, mind you... Oldcom running under openXCOM is really nice nowadays, and it has *very* good mods (and I don't mean Piratez, which I never really liked, although the premise more interesting than that of XCOM2, if implemented more tongue-in-cheek. I have in mind the likes of XCOM: Area 51 -formerly Redux-. I'm waiting eagerly for version 0,9)