Unless you use stabilizing chemicals and want to wait a year for everything to age out, I would not recommend mixing a too-sweet JAO with anything made with a different yeast.
What I'd have done is almost exactly what you've already started, I'd have made a gallon or two of JAO with maybe 2 lb honey and only leave it till it goes dry rather than waiting for the fruit to drop, then add some of the too-sweet stuff and see if it kicks back up... if it does, add the rest of the too-sweet batch and see what happens, worst case scenario you're only waiting an additional two months for this to finish up and clear. If it doesn't kick up, then blend according to taste... And hey, at least it's a JAO on a two month timescale rather than a traditional on a 12-month timescale to see if it's any good!
I found when I tried this early on, eliminating just 1/4 lb of honey with a lemon variant made it pretty awful and I had to blend with something that had stuck, but Fatbloke dilutes it more (using imperial rather than US gallon) and likes it that way, so really, it may be your taste.
I've had one JAO get stuck at around 1.060 which really is pretty sweet, most of mine finish between 1.030 and 1.025, which is sweet but not syrupy, to me anyway. Do let us know what you get when you check yours with your hydrometer!
Oh, and I have found that with JAO's you really do NOT need to sweat about headspace. Most other wines, meads and mels, yes. But there's something about JAO that seems resistant to oxidation, maybe it's the sweetness, maybe something else, but I've never had a JAO or variant oxidize from too much headspace even when I've racked them into a carboy with a few inches of space before the shoulders of the carboy narrow...