No experimenting needed here as far as I'm concerned. The split system perfectly serves the purpose and I thought, and still think that its duality is quite ingenious and unique. Splitting vitality into endurance and health also is an arguably better abstraction of reality than just a single health bar. There's nothing hard or difficult to understand about it as well. Deadfire just needs a similar "training ground" intro like the caravan encampment/Cilant Lis prologue in POE with (optional ofc) tutorials popping up accordingly at the appropriate time and place, and all should be well.