Medium armour is a 9th edition rule. So we'll have to be specific about which book to follow: 8th ed or 9th ed
I'm not trying to diss the project, but it confuses editions.
They started out 8th ed as a bolt-on ruleset with army books for armies that didn't exist in 8th edition, like Brettonia, Beastmen and some more exotic armies. Superb. But then they continued with ravening hordes.
Now, they still kept the same BRB, but essentially the ravening horde books trashes my old army book. They change the army, and the meta so completely that a ravening horde book can't work within the old meta.
Because of the 100 similarities and 100 tiny differences, it might get confusing to play 8th ed and Ravening Hordes alongside each other.
So essentially, Ravening Hordes pushes you to make a choice: 8th ed, or Ravening Hordes.
9th Edition takes it one step further, by giving the BRB the same treatment. It basically requires all the effort of learning a new BRB edition, changes the meta and all that comes with it. This isn't something I can ask my buddies to try out.. It's either "yeah let's move on" or "no, we're sticking to 8th".
From a gaming group's position, there's little difference between going Ravening Hordes or 9th Edition. You either change meta, or you don't. The effort is virtually the same.
My original intention was to stick with 8th ed. There's an appeal to it: we played it, we love it, we have the cards, and we have the books. We know the rules from the top of our heads, even after all these years. We know what a Fireball is worth. We know what a dreadspear is worth. That Shade is a Shade.
We'd work within the framework
and meta of 8th. I'd like to surprise my buddies with a new army composition, but not to the extent he has to re-learn what a witch elf does. His tactics for dealing with Witch Elves shouldn't necessarily change.
Going to a completely new meta is a nice idea, don't get me wrong, but it loses a lot of the appeal 8th ed still has over competitors like T9A and KoW.