Really the least risky thing right now would probably be if BO retooled their lander to fly on a Falcon Heavy. If asked, SpaceX could probably launch 4 Falcon Heavies to orbit before Blue Origin could launch as many New Glenns.
I really don't think there's anything particularly derisked about NG + Blue Moon 2 compared to Starship HLS.
Falcon Heavy has a much smaller max payload diameter (~4.6m) compared the New Glenn (7m), I doubt the landers (MK2 especially) can be retooled to fit without essentially starting from scratch.
The issue is that Blue Moon is designed to have its hydrogen fuel topped off by the second stage of New Glenn, which isn’t possible on Falcon or Starship.