I have Soldiers that receive a singular MUTA pay for over 12 hours of work, does this seem right?

If you’re doing you funerals you’re not receiving a MUTA, you’re receiving a Funeral Honors Duty Allowance. This FHDA is equivalent to 1 MUTA. A minimum of 2 hours of funeral duty is required. Soldiers are entitled to only one FHDA per day.

Do not confuse drill days with any other kind of day.
Drill is the only kind of pay that is authorized to pay "2 days" for "1 day".
Yes, your commanders can use UTAs as they see fit. They only get 48 per year and they are going to use them all for training, not for your state's funeral honors program.
And your state's funeral honors program does not have UTAs, they can only use RMPs.

For clarification:

UTA: (Code 11) Unit Training Assembly (min 4 hours, max 24 hours)
MUTA: Multiple Unit Training Assemblies (traditionally 2 per day of drill; MUTA 4 for SAT-SUN, max 2 per day can be paid, THIS IS THE ONLY CODE that can pay 2 per 24 hour period).
These can only be used for scheduled IDTs or making up a scheduled IDT (SUTA E or K).

Anything else is an RMP (or orders).
RMP: Readiness Manning Period: min 4 hours, max 24 hours, max 1 can be paid per 24 hour period.
Types of RMP:
Code 31: AFTP: Additional Flight Training Period
Code 41: AUTA Additional Unit Training Assembly
Code 42: AUTA for airborne operations
Code 71: Training Support
Code 91 Management Support
Military Funeral Honors (MFH), MDEP - VMBH: is an RMP, authorized, min 2 hours, max 1 can be paid per 24 hour period.

I know that Funeral Honors are awarded retirement points differently than a regular UTA/MUTA.
Funeral Honor details will award 1 point for at least 2 hours of performed duty. With that being the case, it would make sense that they are paid differently as well.