Hey there clasher, try this one out, my line-up is : TG 129 4/9| Atlanticore 120(6 stars) 4/9, GR 132 5/9, Druid 120 4/9 (6 stars), ninja 120 3/9 (6 stars). I farm G 100% unless there's one dwarf trying to clean up the corner (that's why I have atleast one or two griffins in each army camp).
You can use/not use garrisons - up to you, I use them because I don't really care about xp, only about shards.
EDIT: all heroes are at max inscriptions with druid/tg/gr wargod crests.
Hey there i've been using the design for a few weeks now and it worked well but i wasn't able to farm G with out garrisons so i experimented with my base i came up with this,,, My hero line up is "Immortep 6/9 level 140, TG 4/9 level 137, Druid and Champ level 130 4/9 and Grizzle Reaper 4/9, I farm HBM G with no garrisons on this base..