The original feature to "fix" the number of barrels per hp wasn't that bad. It was a good idea because it added "flair" and visible fidelity.
I think one of the "issues" of the Weapon Visuals is the Mechlab. With the option to mount even 3 PPCs in the commandos arm (not that it is even possible but the modells are there) for each weapon hardpoint there is the need of a seperate weapon representation.
However - a better (maybe) alternative is based on the wish of customers to have "hardpoint" sizes.
Spending some time for this option it could have indeed some very very interesting options.
We could differ between energy, missile or ballistic hardpoints or - we limit it simple on weight and size.
Each models location will get a number of sockets with a specific size. After you did fit the sockets to the model. All you need is to model weapon combinations for each socket type.
With the exception of missiles. Missile sizes are direct dependend on the socket - 2 SRM per 1 crit or 5 LRM or 3 ATM per 2 crits....
in a result ballistic missile and energy weapons are interchangeable for each socket:
an example:

Banshee RA Crit 2 Mass 5ton socket
Next a Commando with the same socket size
Next a Enforcer with the same socket (the LAC5 is a "current" MWO AC5) the other weapons are rough sketches of 30min,