It really depends on whether you count "carry potential" purely on how much work the player is doing where obviously scouts and demo are going to be better or you're counting it on how much impact you have on the game with how you play.
Imo pocket soldier is the class where if ur having a good or bad day it has the least impact on whether your team wins or loses, more so than med or roamer. You might still outfrag your roamer but its very easy to see how your mistakes can lose you rounds on roamer, on pocket there are times when you can be fucking up and it kind of feels like you're just there. That said, you still can have a pretty big impact on any class so this isn't to say that the class is useless or anything like that.