Do Weasles in a group get a +1D modifier from others in group?

Given that mice in a group can assist other mice in a conflict (e.g. +1D for fighter) does the same rule apply to weasels in a group? I had one mouse absolutely smash an entire group of weasels by spending a persona point and re-rolling about four axes, and continuously gaining new axes. This one player ended up with about 11 sucesses. I know this is not always going to happen but when you add +1D for two team mates helping with a fighter 6 and the additional of +1D for the mouses trait, suddenly the dice are seriously loaded in the mouse’s favour.

I can’t find anything about Weasels and helping team members in the rules, but apologies if I missed it.

I’ve always allowed groups to add the +D from Helpers, whether mice or weasels, or beavers, birds, etc.

However, I have to say at rare times that even a large group only adds +1 collectively–like, not each individual member is making all that strong a contribution. This is particularly important when allowing swarms fo bees, ants, or termites to act in unison.