[Zu Ra]

Spoiler for manga:

Espadas are Taicho class even higher . Yami is the weakest of Espada , though your idea sounds fun . They dont have to resort to this , simply coz Espadas rarely use their zanapkutos and avoid even first release . So you can guage their power . Till Ichigo fought as Vichigo Grim was using just his bare hands or hand to match Tensa Zanagetsu

The failed experiment which Kaien encountered devouring Zanapkuto and shinigami was his choice of combat . Choice of combat for Espada is on a diffrenet level not these petty things as cloaking reatsu ( Momo Kira Renji ) or devouring a Zanapkuto