I'm not a pastor, but I can tell you about the church I have been a part of for many years. We used to have a very similar situation. Ultimately, we combined to one service and lost a bunch of people, but we are way, way better off for it now.We now have two services that are exactly the same (unless the Lord moves differently in one or the other, which He certainly does), and despite having two distinct groups that tend to prefer coming earlier or later, we are in total unity. If I happen to go to a different service than I normally do on any given Sunday, it feels like I am seeing friends I haven't had a chance to see recently. The feeling, the atmosphere, the spirit of unity, etc. are all exactly the same.