Simpler arrival should shape the choice when onward connections differ: journey time matters, but only after the bus or train leg has been checked. A shorter listed journey is not, by itself, proof of an easier arrival.
How to check the connection
The cited guidance recommends using a journey planner to plan bus and train connections to the port. It also warns that train times shown in downloadable timetables are for guidance only and should be checked with the other travel provider. Those entries are therefore a planning aid, not final confirmation.
Which factor should come first?
If one option has a clearly simpler, verified onward connection, that is the stronger basis for choosing it. If the connections are similarly straightforward, journey time can then serve as the comparison criterion.
Before choosing, travellers still need to confirm the train times with the other provider and check the planned bus or train connection to the port. The cited guidance does not provide a route-by-route journey-time comparison, so it cannot establish which option is faster or easier.