Well i heard here on the forum that wb asuma`s buff is a 1.3 multiplier after all buffs were given so i guess he gives better buffs the more buffs you have from other ninjas. so for example in the standard blitz team (lighting main, danzo, iruka, wb asuma) lets say the main has 10k attack, after the the buffs he would have 110% more (40% from danzo barrier + 30% from iruka + 40% from lightning enhancement) which would put him at 21k attack so wb asuma would multiply 21k by 1.3 so 27.3k attack. While if it was edo asuma main would have a 140% increase which would add up to 24k attack. But if the team had only edo asuma`s buff a 30% increase on 10k would be the same as a 1.3 multiplier so the more buffs the better for wb asuma. I hope my explanation wasn`t too confusing.