John,I looked up blind as an adjective. In old German Blint akin to old English it would be blandon both meaning, to mix more or blend.Maybe in relation to ethnicity a mix of many versus say an all Irish or German regiment.I'm not at my home computer to view regimental history or counties recruited from.
There are several other meanings that might apply,
#2a unable or unwilling to discern or judge.
#3a having no regard to rational discrimination,guidance,or restriction;blind choice.
#3b lacking direction or controlling consciousness;blind chance.
#4 made or done without sight of certain objects or knowlegde of certain facts that could serve as guidance.
#5 Defective
#6a difficult to discern,make out,or discover
I hope this might help.Good luck!
Happy Holidays!