There are a few factors to consider when making a loadout in Bloons TD Battles 2, including small things like upgrades. The first is Bloon-hitting capabilities; players will find it difficult to win if their loadout is completely incapable of popping certain types of Bloons, such as camo-lead Bloons. The second is appropriate level scaling; if a loadout has a weak early or mid-game, a rush from the opponent can end the game before the loadout’s strengths can be used, and a weak late game means the loadout will fall off if early aggression fails.

https://screenrant.com/bloons-td-battles-2-best-loadouts-guide/