Balancing is better, but hard to get exactly. Unless you are camping for months, it won't matter that much. You will be back home in time to "recover" your batts properly before going out again.
I my case with the two RVs and six batts (two 12v T-1275s, two- GC2 6v Wets, and two 12v AGMs) the drill is to keep the two AGMs in the truck camper and the two GC2 Wets in the trailer. The two T-1275s get swapped back and forth as needed, so the trailer has four batts normally- two 12s and two 6s. (Done up as two big 12s in parallel)
The truck camper has its two AGMs plus if needed the two T-1275s get added in as a big 12 in the truck bed wired into the camper to the two AGMs as another big 12.
It all works great. I just have to keep on top of who is doing what to whom battery wise and make sure they all get to their individual 100%s once we are home before returning them to their Floats. (AGMs get their own float)
Have no fear of mixing and matching. Use what you have and get your money's worth. Just stay on top of things. Batteries are not fire and forget.
