maybe, teslas do not receive damage from mara's zap(or, low damage from zaps, and maras receive low damage from teslas).
maybe,a long range turrets can fix it(but,with a little inaccuracy), like natural selection turrets(or tf2) : ), its more realistic(realism,realism,realism, lol XD) and fun, and help to counter crary mara rush, in some situations, maras need a small help from gons/tts for help in cleaning the base(these classes of aliens can receive more damage) like 1.1.
in gpp, is needed only a maras rush to humans win, and the other aliens? are useless or less efficient at it.
exemple, tt and gons destroy some turrets, and maras help in the cleanup (splash damage from zaps+ direct attack of tt/gon = no human base), not mara rush = win.