An elf built pure t/m has to run pure dspecs, how do they hit back out. Halfing running pure t/m your right they can attack. However consider that for a halfing to be "attacking" (using their def) if they want wpa=feary wpa/1.3, tpa=feary tpa*1.5/1.3 they end up running 90 dpa V say 140 dpa. Thats to large a gap when a pure t/m needs to be hard to conquest such that "if you don't bring them down at the beginning, it's unlikely that you'll bring them down at all. It doesn't really have much to do with faery being good at what's designed to do (be a TM), it's just it's resilience to dropping that makes it valuable to kds."
What makes a feary op compared to elf/halfing is its resilience to dropping, that should be an innate ability of running t/m not just feary and The ability for both a elf/halfer PURE T/M to prefer to go a/T/M is what should cost them significant mod dpa loss not just their choice to be T/M.