I didn't read the entire thread (just the first page), so maybe my concern has been addressed.
I went with the second choice, because from a story perspective, Ayla is the right one to replace with Schala, if replacement is necessary. However, from a gameplay perspective, I think the game would be seriously lacking without Ayla. My favorite team has always been Crono, Marle, Ayla. Crono is well-balanced (really strong physical attacks and techs, ultimate-level magic, a very little bit of healing), Marle can heal damn near anything and adds a fair amount to the magic situation, Ayla is super-strong physically...and the dual techs and triple tech with that party are incredible. Ice Sword 2, Falcon Hit, Cube Toss, Volt Bite, Final Kick...just so much good there. Sure, Ice Sword 1 is obsolete once you get Ice Sword 2, and Twin Charm is limited, and that other dual tech of Crono and Ayla's (was it Drill Kick?) is pretty tame, but even Aura Whirl is not without its uses.
Are there suitable replacements? Probably. But I think some dual and particularly triple techs would have to be overhauled or replaced entirely to accommodate the lack of the game's physical powerhouse. I think Schala might tip the scales into the game being more about casting magic than using physical attacks and physical techs, whereas the original was nice and balanced.
Oh well, it's probably a pretty minor concern, especially if we've got people working on it.
Poll