I've never made a GLC deck before but I thought it would be interesting to use ferrothorn and bronzong (a different one from the normal metal links/metal transfer ones). The main strat I had in mind is spreading some damage with ferrothorn's spike lash attack (10 damage on each of your opponent's Pokémon for each energy in their retreat cost) and then ramp up with bronzong's pain amplifier (put 3 damage counters on each of your opponent's Pokémon with any damage on them).