Grays of Berkeley Co/Frederick Co. Va mid to late 1700's.

My Grays were in Greene Co. Pennsylvania by 1790 through present day.  My 3x/Ggrandfather John Gray and his brothers William and possibly James and Andrew Came up from Berkeley Co, W.VA. and Frederick Co., Va.. 

 I am trying to trace my Gray line back to the immigrant ancestor from Probably Ireland as they were Scotch-Irish.Confirmed so far is John Gray and his brothers Eligen and William who lived on the border of Berkeley Co., (present day W.Va.) and Frederick Co., Va. in 1776. Unconfirmed (unlinked) names in the 1750's is Thomas and Robert some time in same area and possibly from Augusta Co. Va. before that. History tells us that 85% of these pioneers to this area were from Eastern Pa. Anybody see a connection here to their Gray family? The curse is that there are so many John and William Grays. It seems to have been obligatory to name your child John or William at that time!