In reality the pilot workload with just a TC would be through the roof.
After any overbanking, the amount of effort and time to regain control with a TC would be very stressful for single-pilot operation compared to the sight picture an AI provides, so I never seriously considered it to be a desirable AI backup.
Conceptually, TC shows a relative value, rate of turn, while AI shows absolute bank.
You can think of the difference kind of like using an ADF vs. VOR - for most people. that latter is more comfortable, especially after some time off, and it’s unlkely they could correctly follow a procedure navigating with ADF today.
I’m saying all this as a 6-pack fan, so the above goes doubly so for a glass cockpit pilot. Love to see some videos of pilots reacting to a sudden dark glass cockpit, especially SP.