Eidolon multiplayer

so i am playing with my friend and we are playing one tec and one Eidolon and most things arent a problem but then we noticed that even when my friend is my ally he will get corruption and in the beginning that is a huge problem. i kept having to gimp my expansion and not upgrade my planets because if he got corruption he was getting -100 in slot of stuff so first of all is there a way to make it so allies get less debuff or none at all the planets can be managed mostly but the biggest problem is when i need to help him defend. when i am defending i am also giving him a huge negative making playing them in multiplayer kinda pointless you cant cooperate or atleast there is little point because of the debuff. when it comes to the planets it would be good if you could limit the spread even when upgrading it to max

hope a solution can be found but love the dlc and game anyway