To take out the goblin horde you either have to use very strong units and use the 100% critical hit spell or drop a meteor on it (which uses a lot of mana)
9---1---0---1-----9---2---0111---09---4-5-1---1---1-----002---7774-82---1---4-4-4-9--c---6---------0---9---0---3-7-0---2---2----1-1-1-1-1----6-0---bbb0--0---2---3-3-3-c--a---3-3-3-0-------a---1---2-2-0---2-2-a-----1---1---1---001---6-6-6-1---0---4-4-4-a-- sorry for all the messed up post third times a charm