Fuse has a point indeed, but the admins are quite experienced and are certainly able to sort up the one round show up with the potential long terms involvements.
We can also take the more formal way(as putting everything on the admins' hands can only lead into endless moaning, and I'm not sure they would be happy of the situation themselves) and put specific regulations on the matter. Possibilities are huge. We could maybe enforce the 3 drivers+45% to specific teams meeting certain conditions, like, for their first ever race, or longer if they're mid-season joiners. Or maybe keep it totally, and give each team(who does the whole season, in order to prevent mid-season joiners from abusing it) 2/3 wildcards per season, which would waive that rule for them during the races they pick.
That 45% rule might have been good 2 or 3 years ago when there still were a lot of interrest within LFS and a lot of teams knocking at MoE's door, but it just can't fit nowadays. Don't expect new blood to come anytime soon in these conditions, just look at GTAL(which is supposed to be MoE's feeder since it's creation, remember), most teams just can't afford going in MoE, because they only have 1 or 2 very commited and good guy(s), who drag weaker teammates for each round. With the 75% rules the best driver can make at least 2 stints out of 3(in case of 3 hours race), meaning that even if the guy's teammate is 1 second off the pace they still have a very good chance for a strong result. This kind of teams would be just sinking in MoE, as you need several good and comminted individualties to do well, which they don't have. They could maybe managed to drag 3 drivers sometimes, but 1 or 2 of them would be off the pace, which would ruin the teams' result, and its motivation to carry on. But if they can do most races with 2 drivers, I belive they could maybe make a sucessful move to MoE.
Well, this is my opinion, maybe someone else has more interresting ideas to propose, I don't know. But I really hope we can get more people interrested in this debate and have a fair discussion on next season, because MoE's future is definitely at stake here.