I'm about to check the feasibility of torpedoes.
Putting standard Type 91 on the Fugaku is somewhat meeeh...
We could instead attach Type 4 - that's basically the Type 91 with a tad more speed, more explosives, and wider drop parameter range.
Then we could use Type M, a 2tons beast running 2.5km at 50 knots.
Then we could phantasize and create an aerial version of Type 93, a 9 meter long, 2.7tons heavy beast running 20km at 50 knots. This would be a weapon where the Fugaku would stand a chance to survive if ships have no fighter cover.
Furthermore we can derive 3 versions off the american Mark 34, let's call it "Type MX".
On is just a straight running Mark 34 clone, another one has a passive acoustic homing head and the last one would additionally have chutes to drop them from altitude.
How about that?
And how about leaving the standard Type 91 out?
Mike