The tents they favor (I'm guessing they are historically accurate) are square canvas tents, not teepees. They were probably lighter than teepees and available from the Hudson's Bay or Northwest company.
It occurred to me that most people probably don't know these things because they don't go to black powder events.
Comments ran about 50/50 for one format or the other.
In the original painting, I was trying to go for the counterbalance composition that Nuttall is fond of.
The "problem" with watercolors is that once you screw up, you are pretty well screwed. There is not much hope of fixing. Acrylics are much more forgiving because you can keep painting over things. Watercolors are good discipline though and they have effects that may be impossible to achieve in any other medium.
Thanks for all the comments. People point out things that don't occur to me, so it is good to get the feedback.