Are Jan Matthijssen and Jan Thyssen the same man?

In De Ruyter's journal, as reproduced in The First Dutch War, Vol.V, De Ruyter writes that captains Jan "Matyssen" (Matthijssen), Dingeman Cats, and Jacob Penssen joined the fleet. I looked at my comprehensive list and see a Jan Matthijszoon who served during the Second Anglo-Dutch War, for the Admiralty of Zeeland. Thyssen or Tijssen could well be a shortened form of Matthijssen or Matthijszoon. If they were not the same, then there would be a "mystery captain" in command of an unknown ship. Jan Thyssen commanded the Vlissingen Directors' ship Witte Lam (40 guns and a crew of 145 men) for most, if not all, the war. He was often De Ruyter's flag captain after late 1652.