Examples of how to conduct complex battles (detailed turn by turn). Everyone must read this!

Taking on the maximum-sized stack (40 griffons per stack) as a rampart on the second week, author - Forrest

We have an Ivor, level 5. Expert in ranged attack, expert in attack. 3-6 (attack/defense).

We attack the maximum-sized stack with upgraded units.
Not on grass. IMHO, this isn't crucial.
The army:
1 Kent, 9 Dryads
70 Kents, 6 Unicorns, 1 Kent
30 Elves, 20 Dwarves (if you change the formation, the griffons will immediately eliminate the elves.)
(The stacks are a bit large. But it's the maximum stack, what did you expect?)
But the army is real, taken from a real game without reinforcements.)

Round 1. White griffons attack the Kents (minus 20). The Elves move to the left and down. Unicorns are positioned opposite the Elves, one square away (they can't reach them directly). The upper right griffons eliminate the Dryads (minus 2). The upper left unit moves next to the upper left griffons. The main Kents move, targeting the Elves in the lower left corner (50 health remaining). The lower right griffons attack the Dwarves (minus 7). The upper left griffons eliminate the unit. The last pack of griffons eliminates the Dryads (-2). The Dryads are on defense. The Dwarves are positioned as close as possible to the Unicorns.

Round 2. White griffons eliminate the Dryads (minus 2). The Elves attack the upper left griffons (damage over 400). The Unicorns wait. The Kents are on defense. The pack of griffons that attacked the Dwarves in round 1 eliminates them. Our last unit moves, positioning itself next to the Dryads between the griffons that attacked them. The upper left griffons fly to the center. The griffons eliminate the last unit. Another one eliminates the Dryads (minus 2). One Dryad remains. The Unicorns eliminate the nearest basic griffons (thanks to the last Dryad surviving and holding back the white griffons).

Round 3. The white griffons eliminate the last Dryad, freeing everyone. (We have Elves protected by 50 Kents, 6 Unicorns (we'll protect them after the Elves' move). In fact, the battle is already won. Using the well-known method of not completely eliminating the nearest griffons. The main thing is to protect the Kents (that is, first eliminate those that damage them). With Blind, the battle is won without any problems (its probability is high, which makes everything easier, even if it happens only once in the battle).

Estimated losses: 3-4 Unicorns, all Kents, all Dwarves, all Dryads.

Addition from Gynnar: This tactic is universal for all factions where one of the combat stacks is ranged (i.e., you can use the same principle to break stacks on the second week, playing as Tower, Castle, but not in such large numbers, since these castles don't have such a powerful level 5 unit as the Elves).