If you can throw 40 EHTs at a seasonal portal where there are 5* you actually want, and during a month when there’s a HotM you wouldn’t mind getting, and there’s a Secret Summon, then…
yeah the chance of an Insanity hero is about 4%
but also the chance of a Kalevala 5* is about 48%
and the chance of a HotM is about 41%
Taken together, that’s still about a 30% chance for no 5* at all (boo!) but a 70% chance of at least one 5* — which is about as good a roll of the dice as you can often get as a F2P.
(I suppose there’s the whole Kalevala vs Morlovia vs Santa question, but that’s also another debate, plus what you think of, e.g. December HotMs historically.)
FWIW:
Beta info on Jul 2024 HotM
Beta info on Aug 2024 HotM
Updated, now that Kalevala is announced for Jul 29 - Aug 9
[ September HotM won’t be reachable via EHTs at Kalevala. ]
Beta info on Sep 2024 HotM