I absolutely admit I dont know all the fine points (I'm a diesel engine mechanic by trade) but ive worked on large diesels for tankers. Theyre a mechanical Goliath, and they cost nearly as much as the tanker. The shipyard that contracted us frequently ganged engines together to a single controls system from Siemens/Fischer or part of a larger command system with a small "service mode" override you could patch a laptop into for diagnostics. Newer ships just send that diag data straight to us over satellite or wifi (sending techs is costly)

Also another problem I noticed is the engines are often on the ships controls (network maybe?) As the manufacturer name. Something like MANN1 and MANN2 or MITSU1 is a dead giveaway: thats propulsion.