The way I'm looking at this C-3PO needs to stop damage three times in match to be better than Chewie (I'm ignoring the point cost difference because I can't really math). It used to be fairly straight forward to work this out for a one Agility ship. If C-3PO always guessed "0" he had a 5 out of 8 chance of being right. C-3PO wouldn't be invoked unless there was damage to block and if he was right he'd prevent a point of damage. I think that works out to something close to using C-3PO in three rounds breaks even with Chewie and using him in 5 puts him ahead.
With the advent of TLT, C-3PO becomes harder to evaluate while Chewie remains the same. There will be many rounds that C-3PO guessing "0" won't get enough evades to matter and guessing "1" will be needed.
Am I looking at this wrong or is Chewie a stronger crew against TLT spam than C-3PO?