in timed matches (20 mins) building clumped arty can devastate an opponent. this strategy works best with UEF, but can work with Cybran
first, tech rust to mass conversion. you want as much mass and energy as possible. If cybran, research proto brain before arty. this will speed up research for your building upgrades
if uef, do not forget quantum distrotion arty.
in either case, when you have mass con, start building excessive amounts of energy generators to supply the mass cons. if UEF, place some near your arty and front lines to repair structures, shields and units.
when this has been accomplished, start lining up artillery before the timer runs out