The Century Club version might need a little break-in time on the track to smooth out. Maybe a lot of track time! I would inspect both locos to make sure the grease / lubricant isn't congealed.
Props for going ahead with the layout. A working layout with O42 is much more fun than an O72 collection packed away in boxes!
There's no advantage to having just ONE command-controlled engine. If you're not planning to run more than one loco on the same track, there's no advantage at all! However if the electronics fail or give trouble, you can always rip them out and install a regular e-unit.
Thankfully, both of your locos have all metal wheels (although the 18058 came with an optional set of grooved wheels and tires.) Adding to what @aussteve posted above, without the rubber tires, the forum would lose another 10% of its threads! Then we might actually have to talk about railroading! Thanks for sharing and I hope your Hudsons provide a lot of fun and no frustration!!