If you want to simply get rid of those extra units in the Player arrangement (Eliwood) slot, assuming that you only want Lyn and that Tactician unit to be there, go to the first level 0 Eliwood, set all of the unit’s values to 0, then save the changes. FEBuilder will then only see the first two units as being there, and nothing else will be listed or show up in game.
Basically just click on the aforementioned Eliwood and make the stuff at the bottom look like this (address, size, and selection do not need to be changed, so they aren’t shown):
image
(Edit: Take a look at this post, it should help you figure out using the tactician’s name: Use the Tactician name on a unit)