There is always a risk that, when a group of people work together, one or two people may be more proactive than the others.
This can be a good thing if the others are prepared to get on with their own tasks and be led, but there will be some who use it as an excuse to sit back and do the bare minimum. In time, this can lead to resentment on the part of those doing all the work and possibly even on the part of those who aren’t doing their share, simply because they feel pushed out of the picture. Careful management is needed to ensure everyone has their roles carefully set out and that everyone keeps to them.