Brokerage vs. 401k - Best allocation strategy with new baby

Hi all! New here but have been in to investing for a decent amount of time and am looking for input on how to allocate my money. I’m 37, I make about $200k/year, and Im expecting my first baby later this year. I currently have 3 major accounts:

401k with employer: $750k total ($80k of this in ROTH 401k) Pension: $150k Fidelity Brokerage: $180k

I having been maxing out my 401k for over 5 years and basically putting it all in pre-tax. With a baby coming, I am now thinking how to best save for them and college expenses. A 529 is obviously the most tax advantaged way to go, but since I have a decent amount in my Fidelity account, I’m wondering if it may be worth it to put some or all college savings in to my brokerage because of the size it is already.

So my questions are:

1. Would you consider putting all or some college savings in to my existing brokerage account due to its current size and existing compounding power? I’m thinking it would be ideal to have at least $35k per kid in the 529 so it can be rolled over to a ROTH IRA for them at some point but I’m struggling with whether to put more than that in the 529

2. Considering where I am with my 401k, would it make sense to stop contributing more than my employer match (currently at 8%) and put that towards kids college? I’m looking to retire in the range of 55 to 62. Which puts me at retiring right around the time my first baby goes to college if I do it at 55. So I’m trying to have that expense squared away before I actually retire.