Strollo already said it,these are very finicky fish and its not like they are not used to being around other large fish..I think it is just the change of moving them and they will feel comfortable and settle in over time.
I'd love to see pics of these Monster Dats
I take it your from San Jose. If you eevr want to sell some or know of any Big Dats let me know. Great Datnoids, Give them time