In Bonzo n Buster - the planes used tiny engines and a small man for a pilot (Bill Brennand) and very light construction.
The planes relied on extremely efficient use of power -being very light weight
they could turn tight - and not snap out .
Many of the earlier contemporary racers use large engines -big radials etc., and were forced to run a more open course.
I still have a page in a 1949 Airtrails with 3 views of all the Thompson Trophy F1 aircraft - showing these planes and the other F1's of that period . There was a very diverse approach to what would work at that time ---
Wittman showed that if you keep the aoa low (low wing loading) - the so called inefficient short stubby wing would do an excellent job (Kick asp)
The later 1949 Tom Cassut racer was much the same setup - and still is a very good machine .
For model builders - I might add that the new BLING by H9 - is almost a dead on planform copy of the Cassut - I have one and it is a extremely good performer - the usable speed envelope is very large. Mine is 1450 sq inches - on a 71 " span and 14 lbs all up - with apiped 40 ZDZ or the 50 non piped ZDZNG - either one - it is literally a VTO setup and has the ability to stop- or fly very slowly with easy, controllable recovery. High sink attitudes are fun to watch. A great big foamie---