Depends on the model . . . for the Osiris, it was MW4 that came before it all just like the Uziel, Chimera, Thanatos and maybe missing one.
Locust 5M, not really sure but I THINK the TRO PP came first as part of the first re-vamps of the Unseen. The MWDA made a appearance in a RS before TRO3075, it was a product early in the Dark Ages line to let folks play with those designs . . . basically if it appeared in the first or second MWDA set it was in that RA with some noted exceptions.
Yeah, the Legionnaire is one that got picked up very quickly by BT- I love the design, the IWM mini works pretty well but the arms are just so thin . . . just too bad its beyond my skills to put something on to thicken them up.