It is tempting to add I, II, III etc to keep different generations straight, but often doesn't help that match because there is frequently an even earlier or later person with that name (after skipping a few generations) that messes up the numbering. In any event, wikitree policy is use the name they used. In colonial America, I've never seen an original document that referred to a person as I, II, or III in their lifetime.
It was, however, VERY common to refer to someone as Jr or Sr. The problem with that is that the Jr and Sr was usually only used during the period of time when both were alive and living in the same area. Before the son reached adulthood, the father would not be referred to as senior, and people generally stopped using the Jr very soon after the father died. Moreover, Jr and Sr are pretty useless if you have 3 generations with the same name in a row (common), which means that the the first 2 were both Sr when they died and the middle one was Jr when he was young and Sr when he was old.
So, all in all, I think best to just focus on their dates and the names of their mothers and spouses to distinguish them.