Slitherine

So I get to the decision where I can reform units, but the text says they will "convert progressively to their improved unit (only if it exists)"

How do you know if it exists?

as long as there is an upgrade path. Provincial units can't upgrade, generic medium infantry can for eg. Phalanx can't, generic HI can.

Thanks. I would have guessed the opposite, given the Marian reforms for Roman legions, so you have helped me avoid some aggravation.