I wouldn't say "probably", I think on the evidence it may rate as "most likely", as otherwise we have to assume Willam Newman dropped dead after the muster, Thomas Ransom kicked out the woman he claimed as his wife in the same muster, and moved in the widow Newman with her two children, and got her to change her name ,which was previously Geren, Garen or Goran, to McNally . A possibility I suppose, one of the children could be Ann, and the other one could have died, before being replaced with Thomas born in 1820 . Definitely a scenario to be considered.
David