Being a gamepad player myself, I think that marking the mobs that are engaging my party w/ letters/numbers is a great idea. Even for fights where links will be of different mob types being able to:
/party <p1> grab <e[nemy]1> I'll get <e[nemy]2> and hold it while DDs finish off <e[nemy]0>.
Seeing as mobs essentially become an ad-hoc party having <e[nemy]0>...<e[nemy]7> like we have <p0>...<p7> seems to make sense.
/assist [puller] is still useful allowing everyone to target [puller]'s target before it gets engaged and before the ad-hoc <e[nemy]> party comes together.
and /target <e[nemy]#> would work the same as /target <p#>
I would suggest that w/ this targeting you ensure that <e[nemy]#> remains unusable until the <e[nemy]> party has been fully claimed or it'll turn into a cheap NM grabbing tool where all you have to do is run around mashing a macro that:
/target <e[nemy]0>
/ac "Provoke" <t>
That would be bad as I don't think we want to help claim bots too much.
Otherwise this is an awesome line of thinking, Thanks Riaayo.