Co-op Difficulty scaling?

I'm a filthy casual with just under 100h logged, and everything unlocked.

I usually play in Standard difficulty, occasionally in hard, mostly because since I can't stop a run any time (still not sure why it's not an option; to save at any checkpoint, at least for solo play), and I prefer to complete an entire run versus quitting or dying on purpose

If I play on Easy, I can breeze through the game without any challenge whatsoever, barely touching the ground, headbonking, slamming, etc, and never be under 3/4 health.

However, if I play with my buddy (who's less skilled), also in Easy mode, we are both knocked out before we get halfway through phase 3 (Fields/Aqua station). Seeing as we're both at half or less health when either of us gets downed, it's pretty tough to recover once one of us is knocked. I'm trying to help him farm for some of the unlocks, but it feels like we'd have to go down to Discovery in order to do so, which seems a bit strange.

I guess I am surprised that Easy in Coop feels more difficult than Standard in Solo .. I understand it should add extra enemies to balance things out, but are these enemies also hitting harder with more health? I would have guessed that Easy Coop would be harder than solo coop, but easier than Standard Solo -- have the devs shared what the changes are to the enemies in coop vs solo?