let's explain:

V.T. Marvin' adaptation:
as far as I know:
he used 25 legions. To get for every new office you should take 3 provinces. namely 1 legion for 3 provinces. he changed +1 management bonus with +1 command for legions. (I also tried to do this but I had no idea when I tried it froze my game all the time )

may last version:
35 legion commander. I added their descriptions. to get the legion commander offices (legatus) you should take 50 provinces cos I adapt my EBBS script marian control with unconditional 50 cities.
legion commander still have same bonuses why I explained above. and of course I changed legion banners.

these must be the main differences for detailed ones you should ask V.T. Marvin.
As I do not like playing Romani. I do not care the numbers of legions but many likes named legions.

I hope it helped a bit.

P.S. Please send your images or image links for my main post so as to show the offices. My PC sucks so I get many a ctd