Is it REALLY that bad to have too much formula? What would you do?

I saw my HV 2 weeks ago for little ones 9-12 month review, she said he's probably having too much formula and to cut down. He's 11 months old and has 26oz per day over 4 bottles. I know it's probably more than the average 11 month old. He just LOVES his milk. I would say he eats average amount of solids.

I cut out his mid morning bottle and since then he has been really restless through the night, usually he sleeps 7-6/630 but he's been waking up at 3, 4, 5. Yesterday I let him have 4 bottles, just to see if it made a difference AND he slept through!

What do I do? Carry on with 4?

If I wasn't 9 weeks pregnant and struggling with exhaustion, I'd carry on just giving him three and hope that over time he'll sleep better but I am just so so tired 🙈