It all depends on what you are doing in the trailer. Living in it? Weekend cottage?
The OP asks can this work, with split bank etc, so answer is yes, but that way is not necessarily what most would recommend for the job.
Why does the OP want to have one battery at each end of the trailer instead of putting both together at the front? We don't know enough.
Best way is to ignore the converter unless you have a generator, combine four batteries (get two more) in one bank a the front, connect the inverter and plug the shore power into it (unplug the converter!!!) Use all 400w of solar on the big battery bank (might need two controllers if that is two kits, but the two controllers can be in parallel on the one bank.)
You can set up the solar panels tilted up facing South on the ground or on the roof of the trailer or you can build a "contraption" so you can turn them towards the sun a few times a day to keep it aimed.
Many ways to do it and they all work. But what is "it"?
