Just ascended a hobbit yeoman in Slashem.

This time I had an exceptional amount of wraiths leaving corpses and I
enhanced the hobbit to XL:30 quite early - being Lawful I had no fear
of Astral's angelic beings (or titans) inducing summoning storms.

With that high experience level the minions I got from sacrificing at
that point where Solars, and eventually I had a guard of three of them.
I had a close look that they don't get lost (by levelports, engulfing
monsters, or polymorphs from traps or genetic engineers). These Solars
killed almost everything, the Angels and Priests, the Wizard, and even
the riders; Death (thrice), Pestilence (twice), Famine (13 times). - My
hobbit yeoman hasn't killed any instance of them. His terrifying weapon
was a blessed magic whistle!

The fact that I had to visit all three altars wasn't an issue in this
game, given that I just had to concert my minions appropriately. The
only (minor, if at all) issue where the player characters; even three
Solars around them many turns could not kill them - so they got simply
teleported away (while cautiously avoiding line-of-sight with the zap
to not target the riders or their corpses).

Once you get there (XL:30 and Minions) you're quite unstoppable; a bit
unbalanced, I'd say. If I compare that with non-Lawfuls that regularly
die to summoning storms, e.g. at the Plane of Air - which I also think
is very unbalanced,[*] but here the other way round.

Janis

[*] The same for Nethack, BTW. Any exponential effect should be limited,
IMO. Which could be achieved by requiring more Mana-energy to cast that
spell and more time to recover that energy.