It occurs to me, further, that ANY non-material effect or factor is going to have to be depicted on the table somehow, unless it is noted on a roster off the table. If a unit is in disorder you can sometimes show that by misaligning minis or stands — which however takes time and requires extra handling — but if a unit is nervous or elated, those psychological states must either be noted on the unit’s sheet or else be marked on the table somehow. If keeping the table clear of clutter is the priority, I don’t see how to avoid record-keeping. Your compromise may vary from mine, but I am willing to put up with the markers in order to make the game run faster.
I have never played modern games including electronic warfare; how is that handled? I assume that magic — at least spells targeting commanders or morale, non-tangibles, would have the same range of choices?
Of course many magic spells do have a visible effect, whirlwinds and fireballs and such. And while spirits (good or evil) may be invisible, I think the convention of depicting them with minis is widely accepted.
Finally, I will add that we have found, and continue to find, pleasure in searching for just the right mini or marker to depict a particular spell. Several of our spell lists include “Ill Wind” which requires the targeted unit to roll twice and use the worst result. I’m thinking of a small base — a penny — with a pair of tiny dice glued to it, showing snake eyes. If I’ve choosen wisely, the kids need no explanation to understand which spell that is and what it does.