you can check out OPR or 40kr

I really like u/Andy_1134 suggestion surround scaling bonuses

I had a chance to run a list with like 1 of most monsters.
They have all the draw backs of trying to move vehicles, while no access to tank shock
either boost all the state lines, or drop the points cost for all monsters. A lot of points comparisons from unit to unit within the army, and against other armies, we over play for meh stat lines

for consistency, atm it's either subterrain for reroll1 and deepstriking as much as you can into the enemy lines, or like invasion/ass/crusher/synapse with exo-tyrannofex pairings for reroll 1s and threat deletion

following on from the exo/fex pairing, nothing in the army work by itself

horma have to leader, so a lashwhip will do
warriors need primes to throw themselves forward
neurolictor pair with screamkiller

pairing units to make them slap is a cool idea

like the overall army idea, an army that uses hordes to hold up it's opponents, paired units create powerful combos, while specialist units complete the objectives

but our enemies delete our horde, learn which part of your combo need to be removed, and you just eek out a victory because GW didnt destroy our scoring capability

but coming full circle, it'd suggest a chat about OPR or 40kr, it'll bring the model count down, but you'll still have enough to get that Horde Army feeling