I'm not sure Coley has had a better Wigan career tbh. Is it not just that expectations on him were a lot lower then they were on Fielden?
Fielden helped keep us up starting his career in good form, then lost his form, re-found it again, won a grand final and then won his international place back.
Coley started his Wigan career slow for a couple of years then like Fielden everything picked up for him under Maguire.
People always judge Fielden against expectation which was/is huge when in reality if you just look at his form minus the reputation and it's been as good as any prop in the league over the past few years bar maybe the big guns of Graham/Morley/Peacock.