There is no motivation for Tour legend to play one tier below. Or any tier wants to play lower tiers. So it means lower tier player can not see how top players play. That means they do not buy new club because for lower tier players do not have motivation or they may think its beyond their reach.
So making top tier players play lower tier player with some kinda scheme ( in this case good chunk of bonus points) one tier less 100 , 2 tier 150 , 3 tier below 200
one TL playing with Legend gets 100 points. Tour master 150 points
Scheme can be per player (bonus multiplied by players) or just atleast one player.( just each different tier).
It is better way is give bonus for different tier in the team.