Crawford has had some terrific BABIP numbers, .247 last year, .269 the year before. Bello has been .306 and .303 respectively, which is more in line what you'd expect. That Crawford has over 200 IP at that level, does it mean he has a special ability to miss bats? I don't know.
Crawford DEFINITELY had a problem with homeruns last year - and there was an uptick in the barrel rate last year per Statcast.
The two have similar lines - but I do think the stuff and the age gap is enough for me to still have more hope for Bello to be an above average starter than Crawford.