For those at all interested in xG-type stats, Angelino has the third highest xA (expected assists) at City - only behind Mahrez and KDB. The caveat, of course, is that he only played 417 minutes, so it's hardly conclusive, but it certainly suggests he had/has promise as an attacking full-back. His xA is higher than Alexander-Arnold and Robertson. Incidentally, Cancelo has almost the same xA as Robertson, although once again, it's only from 664 minutes, so you can only infer potential at this point.
So, if they performed exactly as they have done during their few appearances for us in the Premier League, our backup fullbacks would produce more assists for Liverpool than their "world-class" attacking fullbacks.