They are both stunningly average. Senchenko would be the easier scalp. Once Isaac lost that massive size advantage at lightweight, his effectiveness decreased.
Hatton would still steamroll Hltaswayo, I think. Senchenko might be able to box him from the outside and use his major size advantage to win. Senchenko is kind of like a longer version of Collazo, IMO, and we remember the kinds of problems Hatton had with Collazo.
He did this once before with Callazo, who turned into a real name by nearly losing to the guy. I it much the same, with the beating them badly for the first half and then surviving against them in the second half if they are still up and about after the 6th.
I like Hylatswayo and the guy can fight. Suschensenko (spelling?) is an unknown but ilike many Europeans is probably well schooled and a good fighter. Not easy picking but not a bad idea for Hatton. Easyer then Pac Floyd or Moseley or Clottey