There are some people on this Forum who are "allergic" to the term "lash-up"!
But Lionel does use the term in L/TMCC for controlling several engines on one train at one time.
You can do that with L/TMCC. In the MTH DCS world, it is also possible with PS2 and PS 3 equipped power. It can be done with MTH with DCS and PS1 and PS3 equipped locomotives. I'm not into DCS, so I will let those people explain.
It can be done in DCC also, but I have only run DCC on a HO scale layout.
Have fun