As pinuz1 said so well in his post, unlike some other games where our MC is a blank slate, here we have a MC with some background. Ian is dwins best friend by far. He never had been bad to him, on the contrary, Killian would probably take the literal bullet for Edwin. Also some flashbacks and dialog shows that Ian was not always the ass to women he is now. This all began to get traction since "good, old" Uncle Chuck got major influence on Ian. And Grace being a Mom in name only did not help either.Yeah, you're right about being different -- i simply don't get the "being neutral" part when Ian has been an asshole to Mina when they were together. Or how Edwin can consider himself "a very good friend" to Mina in this case, when he apparently doesn't give a fuck about how his other very good friend has treated her and is instead just giving him a pass.
If paying back something for Ian´s friendship is helping him get his north again, is a no-brainer!
Mina grew on my Edwin very fast and I tried to help them. I told Ian when we could do so "You have a great GF. WTF are you doing, man?" and after their break-up told Mina that currently she should not be with Ian. If now a contemplative Ian and Mina find a way back together, that would be great for my Edwin. If they find out they need other LIs to be happy than my Edwin will be happy for them too.