magnate whats your god ?
perhaps you should leave him at home rather then furthermore leading gigants and summon/forge
furthermore : you could well decrease upkeep by sacrificing all your gigant units and using summons instead .
at the point of the game in which you are now the gigants are not much more than fodder too .
unfortunately 40 gigants are really normally not enough to take out 180 other units because they swarm them to death .
you could use some of the "goblins" i think they are called vaettis with your gigants as another solution :
they swarm , the gigants hit easier + kill .
iirc gigants are size 4 and the vaettis size 1 .
so 1 gigant + 2 vaettis can occupy one battlesquare

.
the only
troops always worth being produced which are still very strong lategame are imho :
devils , vampires , storm devils , torrasque , abominations , ghosts .
of these ghosts + vampires are the best imho because you get them as freespawns (summon allies) from good sc leaders :
ghosts from wraith lords
vampires from vampire lords
200-400 ghosts / vampires can take out almost every AI force without support even lategame .
10-20 abominations most likely too .
one of my favourite sp lategame force :
storm demons with pazuzus and the air queens
