To my best knowledge the record is still 8 in the "bound" form.
(I once did 8 myself, but "free".)
Does anyone know a Fleck with more than 8 variants?
*NO* random batteries. (Which means, a matrix e.g. Ra4 Sd4 - Kf4 Be8
with Se6/Se2/Sb5/Sc6 is OK to me.)
Otherwise, I'd take a look at any fairy. But be sure that I can
"design" myself to get an arbitrarily large number of variants.
So there are things that I don't consider cheating (wK in check,
promoted material)...and some I do :-)