I do think that teams with fewer members still actually have a small statistical advantage, despite the scoring method being used. Not a gigantic one, mind you, but every statistical advantage is worth a consideration in a game like this. Here is my reasoning.
The more members a team has, the higher the chance is for that team to have members with only a few 1-ups (like just a single one for example), and the more members a team has with only few 1-ups, the more these members weigh down the high-scoring players of that team in the average score. In fact, Boshi's decision to automatically convert leftover coins into 1-ups could end up harming some teams, because there might be members who didn't even plan to participate in the game because their coin count was too low, or members who signed up for a team but then forgot about the game and didn't get a lot of coins. Some of them might have just barely made it above a single 1-up and now they contribute to the overall score of that team and potentially weigh down its high-scoring members
Her's a simple example to visualize my considerations. Imagine team Red Yoshi had 20 members and team Yellow Yoshi had 10 members. Now imagine that only half the members of each team were active players making at least a single 1-up. Now imagine that there were only a few high-scoring members in each team. Let's say three for team red and two for team yellow with each earning ten 1-ups. That would calculate their total 1-ups as follows:
10 + 10 + 10 + 1 + 1 + 1 + 1 + 1 + 1 +1 = 37
10 + 10 + 1 + 1 + 1 = 23
Now divided by the number of players with at least a single 1-up in that team, that would be 37 / 10 = 3.7 for team red and 23 / 5 = 4.6 for team yellow, so in this example, team yellow would actually win, despite having fewer high-scoring members, just for having less active players overall.
So basically, a team with more active members overall also needs to have a proportionally higher amount of high-scoring players to offset the low-scoring ones, and since I assume high-scoring players to be rare and distributed randomly across the teams, I do think that teams with fewer members statistically have a slightly higher chance of winning. Granted, it's not a huge difference (and for all we know, even just a single high-scoring player might end up making their entire team win, regardless of member count), but in a game of chance, it's usually wise to utilize even the smallest statistical advantages.
In fact, this thought process is what has led me to pick team Yellow Yoshi, which I assume to be the least popular one and thus have the fewest members. Had the scoring rule not existed, I would have gone with Blue Yoshi simply for being my favorite one, but I did think that joining Yellow Yoshi would give me at least the tiniest little staistical advantage, so I went with that instead.
Now all of this is assuming I even understood the rule correctly, which, admittedly, is forumlated a bit ambiguously. It reads:
Originally posted by Boshi
[...] the winning team will be calculated by the total 1ups for that team divided by how many users have earned at least 1x 1up.
I interpreted the last part of that statement to mean "by how many users [of that team] have earned at least 1x 1up", but technically, this isn't explicitly stated, so in reality, this could also mean "by how many users [of all participants] have earned at least 1x 1up". However, if the latter was the case, then teams with more active members overall would have a massive advantage once again (10 members of a team with 1-ups divided by 11 members with 1-ups in total would obviously put the team with 10 members at a massive advantage), and since the scoring rule is meant to prevent precisely that, I'm assuming that the first possible meaning is what actually has to be intended here. Otherwise the rule might as well just not exist at all and it might as well just be a regular sum determining the victory of a team, it wouldn't really make a difference.
--------------------Feel free to visit my website/blog - it's updated rarely, but it looks pretty cool!