There are three geographic groups with early "Trumbos": PA (now Montgomery County); Virginia (now Rockingham County); Maryland (now Carroll County)
Spellings include: Trumbo, Trumpo, Trumbor, Trombore, Thrumbo, Trumbower, Trumbauer, Drumbore etc.
Y-dna tests of male Trumbo descendants would show which Trumbo groups share a common male ancestor.
Trolling the internet, always a risk, suggests these relationships (***UNPROVEN***).
Andrew Trumbo 1 (Mary) of now Montgomery County, PA may be the common ancestor to the Virginia and Maryland groups below. He had a son Andrew 2 (Luise) who remained in the same general area. This Andrew (Andreas Trim & Mary Magdalena Schopp) is the person and family, who migrated to America in 1710 and are mentioned in the Simmendinger Register.
H. Jacob Trumbo (Mary) of now Rockingham County, VA is the most studied of the three. He had four sons: Andrew (Margaret) to Bourbon county, KY; John (Mary) to Alleghany county, PA; George (Margaret) to Pendleton county, WV; Thomas jr (Elizabeth) remained in the Brocks Gap area of Rockingham county, VA.
Adam Trumbo (Henrietta) of now Carroll County, MD is claimed to be the son of H. Jacob Trumbo of Virginia; George Trumbo (Mary) of the same county is claimed to be the son of Andrew 2 Trumbo of Pennsylvania.