Looking for some help because LO2 is SO different from LO1, and he's not following any of the normal eating patterns. What/how do you feed your 8+ month old?

LO2 is in the 5th percentile for height and weight. He's a tiny little dude. At 6 months, he dropped to second percentile, but had him in for a sick visit recently, and he's back up to 5th. Because he's so tiny, the doctor wants us to keep feeding him based on our current schedule, and we introduced solids at the same time. He is at 36 ounces/day not counting what we mix with his solids, and the pediatrician isn't concerned since he's so small. His schedule looks like this right now:

7am - 7 oz.
8:30am - breakfast (solids)
10am - 7 oz.
12pm - lunch (solids)
1pm - 7 oz.
4pm - 7 oz
6:30pm - dinner (solids)
8:30pm - 8 oz

He drinks his bottles like a champ, but his solids aren't great. I'm trying to figure out how to get him to take less from his bottle and more solid food in order to wean him shortly after he turns 1. He's also a formula baby. We breastfed until I went back to work at 4.5 months. Please, no judgement. That ship has sailed.

Any advice?