Until now I've always left the Default #1 setting on all of my engines due to the fact my layout is so small and I only ran one engine at a time. However, now I'm going to assign 'unique' ID numbers to each of my engines to enable me to run two trains simultaneously on two independent loops using one Legacy CAB-1L & BASE-1L system.
My initial inclination is to assign the same one or two digit number to each matching engine consist. However, the main reason I'm asking (before I start assigning numbers) is because occasionally in the past - on some of my brand new TMCC equipped AA matching engines (eg. B+O F3 AA set, 6-14565) - for some reason Lionel assigned #1 to the lead powered unit and #2 to the trailing unpowered unit? However, I've never understood the need for this - at least in my case, given my small layout and the fact I don't foresee me ever trying to make up a 'Train' consisting of multiple different engines.
Anyway, any thoughts or comments would be appreciated. Thanks.