Did it matter where the two types of torpedoes were loaded?

It most likely did. That would be based on the requirements for the TDC. A single spread or salvo of torpedoes probably needed to be of the same type. Otherwise, the TDC would need new information about the type of weapon being used in the middle of the firing sequence. The best situation would seem to be to load all of the same type torpedoes in each torpedo room. It could be different forward than aft and could still require the TDC to be reset, but it wouldn’t be in the middle of an attack.