I don't have any suggestions for you, because we're still on 4 bottles. But I find it interesting that your ped thinks that at 9 months old they should only be on 3 bottles. At our 9 month checkup, our ped said 4 bottles was "perfect" for our ds. I did talk to her about dropping a bottle, and she told me to let ds take the lead on when that is, because "he's only 9 months old". Which was also my thinking at the time, but other people were making me think I needed to drop him to 3.
Anyway, we're still on 4 bottles a day. I may try him on 3 bottles a day at 10 months or so, but we'll see.
Oh - and I do bottle after solids all the time and have been doing that since he was probably 7 months or so. I just do solids first, then wait 30 minutes to 1 hour later for the bottle.
Good luck!