Honestly pikmin 3 feels like a sequel to pikmin 4 more than the other way around IMHO. the multiplayer is superior in every way, the second screen is used in perfection with the split control system (GOOD DANDORI REQUIRES SUCH).

It's really really good.

Absolutely! Play all the Pikmin games! Especially since you already have 3.

I think that 4 feels closer to 1 and 2 than it does to 3. I guess 3 has more of a focus on efficiency and problem solving compared to 4 which seems very combat focused?

Imo 3 feels different enough to be worth checking out, especially if you already have the game.