About the FF characters in KHI

Just finished playing the game... is it just me, or do the FF characters in KHI seem really different from their usual selves? For example, Aerith seemed unnaturally reserved and serious despite how flirty she is in the original, and it appeared to me that Cloud and *Leon* almost swapped personalites entirely to the point I even begin to wonder if maybe they really were swapped by mistake, but perhaps this is just me.