I agree with the above statement, I think 3 batteries are definitely best for 200 watts.
I don't know of a lot of mods that reach 200 watts that are internal batteries either...
I actually think my tesla nano performs better with dual batteries. I don't see why people push 200 watts in to dual batteries, the battery life of my alien is terrible compared to my tesla nano.
For 3 battery mods I'd go for wismec but many might disagree, I don't have a lot of money for mods. I am a poor vaper haha.