I always get nervous with engine counts of more than 5. The Soviets (as you might recall) never developed the large-capacity engines (like the Saturn V’s F-1) and relied on multiple smaller engines. Their moon rocket (the N-1) might actually have succeeded IF the first stage didn’t have to rely on the perfect sychronization of something like 22 engines.
To me, more engines = more that can go wrong.Today could be mild proof of that.
Another thing, the one area where you could have extra capacity without too much of a weight penalty would be engine size.
No doubt they'll get it figured out in a timely manner. That's the great thing about private enterprize!