2 people army VS level 3/4 raid bosses

Any level 3. Probably no level 4s at that level.

All lvl 3 should be easy relatively lvl 4 don't know ( never did any )

Probably all level 3, depending if you have the right counter mons...
But I give you no chance for level 4 bosses. You can try a Rhydon if you have lots of maxed out Vaporeons. But even though, I don't believe in your chances.

My son and I are at that exact level. All the level 3s can be defeated, but no chance against level 4 mons.

Level 3, all are possible with 2 players.
Level 4, probably only Charizard, but both players need a team of 6 double rock Golems at minimum level 30.
I doubt any other level 4 can be duo-ed at this level.

Y'all should be able to SOLO Level 3s and below at Level 33.