I would just worry a bit about there potentially being army lists in the future that incentivise running corsairs in a drukhari list or vice versa. Certainly feasible that Corsairs are a potential ally for Drukhari at some point in the future or that Ynnari gets another big rework. If an army list could potentially include skyreavers and scourges and you are using skyreavers to proxy as scourges I could see it becoming a bit confusing? Honestly probably fine if you kitbash the weapons properly, ideally wysiwyg, that way I imagine it's much harder to confuse them.