It actually implicitly thinks that the extra income is shared evenly between all other players. Most of whom are noobs.

More specifically, it doesn't care about players at all: it just compares team averages, so having more/less players is just ignored. EG if you have a team with 3000, 2800, 1600 and remove the 1600, then the average jumps massively up and it thinks that's great! And i actually suspect that quite a few ZK players will also think that kicking the 1600 would boost the win chance of this team.

The part where this becomes a mistake is that sure, increasing the team's average skills by dropping players diminishes the amount of mistakes the team can do (because it's higher-ranked on average) - but also, it reduces the amount of things it can in general do at all (because it has less hands for input). And actually often doing wrong things right now is better than doing right things too late.

Unfortunately, we have no real way to evaluate the size of that effect.

( At least, precisely, so that it can be used by an algorithm to balance teams; we definitely can evaluate it as "this sucks, what the fuck" - but that doesn't help )