Never seem them before.
In my opinion the way they are scultp could be a test of vampire count figures (but I am guessing, have no idea).
The way the flashes are in the base (air vents) remainds GW, but it is too bold guarante the GW casting only by the flashing.
They are not pendraken, irregular, coppelstone, old glory or kallistra.
The human archers remainds me old glory but not know that old glory could have figures like them. Skellies rchers bowmen are not GW style, but as a test strip all can happen.
Are they marked on the base? some unreleased GW uses to be marked by hand with letteres GW.
hope it helps