So do you want to pay 20X more for funds that likely will under-perform the index funds?
A risk on the rollover is that you sell low, and while the money is in-transit, stocks go up and you wind up buying high. The check can be in the mail for weeks sometimes. Note this can happen no matter what the current price-level is. The best way to mitigate this is to transfer in-kind if at all possible, then change to the new funds at the new brokerage - minimizes your time out of market. A call to Vanguard would let you know if they can facilitate this - some proprietary funds cannot be transferred in-kind. Also, in the grand-scheme of things, $37K isn't that much, so even if you take a substantial hit doing this, you'll be OK long-term.
At the ER's you've got on the index funds, I might consider rolling the old 401K into the current 401K - .03% is better than you can get, even at Vanguard. VTSAX (with $37K, you get admiral shares) will give you a bit of small and mid-cap exposure that you don't have in an S&P 500 fund, so if you want that, .05% is a good ER too. Not really a bad choice either way on this rollover. Then if you want bond exposure, you can do that with the Total Bond Index fund as well. Personally I go 55% VTSAX / 25% Total International / 20% Total Bond, but you should determine your own allocation.
Think about your risk tolerance, then come up with an Investment Policy Statement -
https://www.bogleheads.org/wiki/Investment_policy_statement. Then when money comes in, you don't have to think about it - just buy whatever your IPS says to buy.