Think you've got the nub of it there, Danny. Though not such a marked difference to the contrasting engines that you instance, the Hercules 216 engines (1800 bhp) of the Hastings were extremely reliable. I experienced only one shut down in anger while operating them, and that was due to the failure of an external oil pipe rather than of the engine itself. Its big brother though, the Centaurus, was rather less reliable. As fitted to the Beverley, the 173 variant (2850 bhp) always had a prodigious thirst for oil.
There proved to be a slight snag in Court Line's cunning plan when they obtained a Beverley and put it on the UK register, as it was then the only UK aircraft capable of carrying an RR RB211 internally, in order to enable a quick reaction engine change down route for its two L-1011 TriStars. The slight snag being that the Beverley's Centaurus engines proved to be more unreliable than the RB211s it was meant to shift!