Irc the NP11 reached the front before the DH2. There were a couple of DH2s posted to France in 1915 but actual squadron deployment started in early 1916, same as the NP11. Before then single seat aircraft were attached in small numbers to 2 seater squadrons rather than being deployed solely in single seat units.
What's needed are 1916 era 2 seaters, I'm sure 777 have some planeed. I can understand people wanting to start career mode as early as possible but at the moment, the planeset just isn't there. If you're happy with Nieuports pretending to be 2 seaters and such then go for it but I really don't see the point. From mid 1917 onwards its great
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