Honestly, as someone who played FFH extensively years ago, I see no problem in just keeping the name Fallen Enchantress for this series. I know Kael once wanted to make FFH into a stand-alone game, and I think had plans for it at one time. But now Fallen Enchantress is his baby and has many similarities to FFH. Why not just make a future Fallen Enchantress 2 game with FFH in mind. Like Fallen Enchantress: Fall From Heaven. With what I expect is a new engine eventually, I'm sure Kael would have all he needs to add the lore and special aspects of that game (which also was modded extensively by others). FE basically fits the FFH mold. I'm not sure having 3 or more separate 4x fantasy games would work, unless Kael plans to do this on his own someday.
hmm...and actually reading about SK, there are aspects of that game that remind me of FFH too.
Otherwise..yeah...stick with "Elemental". You've redeemed the name. It's simple and quite nice sounding really. Ha..yall have made this so complicated. If you decide on Elemental 2, then you can go back and re-brand the FE stuff.