When I originally proposed the MD90 and MD95 fleet combination strategy in the forums, it was presented as a way to bring a third competitive narrowbody into AWS as an alternative for the players who want to think outside the A&B box. I find it is great that the fleet groups have been merged and the paper plane MD90's have been added. I also enjoy how they're competitive in nearly all respects to the A&B planes. Since I just specified nearly all, let's talk shortcomings -
The main issue that I'm seeing with the fleet group is that they trigger plane is too small warnings far earlier than the A&B counterparts. For those located in Europe and other areas with a lot of short haul international flying (and probably other areas on the world, except for the US), the MD90/717 fleet group will trigger the plane is too small warning much sooner than the A320/737NG families will due to how the fleet types are split and seat counts are averaged. I've seen on some routes with 800-1000 demand out of LHR where the MD90 is too small at 1500-1700nm but the A320/737NG is not. It seems that the "too small" warning was designed with the seat sizing of the A&B group averages but not revisted when the MD90 and 717 got their groups combined. As a consumer that has flown on all of the types in the families listed, I do not discern a difference in comfort across any of them (actually, I prefer the MD jets for actual flying due to the 2/3 layout).
From a game balance perspective, it would make sense that for these 3 slightly different but similarity equipped fleet groups should have a comparable "too small" ratings. Since I doubt you'd want to introduce a few models of the MD-90-70 or MD-90-75 to balance it, perhaps there's some magic on the back end that can be worked.