Who do you have that is a critical leader? That’s where you start. Hopefully a yellow because guardian 2 Zeke, guardian 2 Rick and Gator would compliment that well
If you’re trying to build a team to get towers you shouldn’t use 6*. They tend to use their active skill and that just slows you down.
Tower team definitely is different. I took it their question was a generic zombie team for maps.
It doesn’t look like you have any legendary crit leads, so pick up 5 star red Rick from the supply depot when you see him. If you started relatively recently you should have had the ability to choose red Carl for a mission completion early on. Hopefully, you have him, but if not here’s a list of some other useful five stars for either their rush or lead skill. The last one is Conner who can be obtained from the ascendance tower.
I remember using 4* Molly for a very long time even when I had 6* until I got Barker for fast teams
There’s also a 5* blue jesus with crit/hp for ranged… Revive rush