I thought the model T had a belt driven generator with an attached voltage regulator. I seem to remember having to polarize them depending on whether the vehicle was positive ground or negative.
But I only played with a few of them.
A starter is just so simple, to have to add a freq-drive, and the logic to control it seems like a waste when the current starters are so reliable and inexpensive.
Imagine if your flywheel has a stator mounted in it, and you burn up a coil. Now to fix your alternator/starter you have to separate the engine and transmission.
This is the way many motorcycle engines are, except that the flywheel is easily accessible for repairs.