Anyone in this situation before or currently?

You were a beta in a past life and had a friend who led the way pretty much in all scenarios. Since then you've grown and taken that leader role in quite alot of friendships and relationships. Thing is that guy who was your friend was your best friend and you've stayed in contact for years. Due to past precedents, you either:

a) argue constantly

b) fall back in that role

For those of you who have or are in this situation, what did you do?

Thanks