umm i do know some stuff but i don't know if it will help you
for a game i've played you'd have to input a command like
{on:hit,
;script, "blahblah" 0,0,0,0
; end,
i-; end,
; end,
well w/e it went someting like that
i've never tried to input a script command into glest so idk but the skills that the units use in glest is that which ever skill is input first they use
also i think you'd have to put something to make it check if it is land or air and if they are both the same do something like a ratio........w/e that is