Thomas' grandson Robert Symes, Sr. currently has a pending merge https://www.geni.com/merge/compare/6000000132025112821?to=600000000...
I believe this is an accurate match, however, I am not familiar at all with this family/era/region so am not going to proceed.
One of the issues that gives me pause is that the grandson Robert Symes, Sr. currently has two sets of parents after a recent merge, so that needs resolving.
Second issue is that both Robert profiles have a son "Robert Jnr" but the younger men do not look at all like a match. I suspect one Robert may be a "Robert III" or from a different branch all together.
I’ve separated Robert Simms, Jr. from Maj. Robert Simms
I could be wrong, but so far I think Maj Robert is from a different line.
Further research needed.