If a Spad XIII or SE5a was added to the lineup you would see some Boom and Zoom to go along with the
Fokker Dr1 turn fights. You would also see more pilots using the DVII and Camel

I doubt it. The numbers basically do not support it.
The environent shapes the fight, the kind of fight largely dictate the choice of planes.
When there are so few players (I always see 0-8 on my loginscreen), the battles more or less naturally end up in dueling style "fights".
When there were still (relatively) huge battles in the WWI arena, the most used & successful plane was the boomin' and zoomin' D.VII. Only when the player numbers went down, the Dr started to rule, because the nature of the fights changed.