tough shard
By "types" I mean (the ones you see in the photo). It really isn't going to be useful for experienced players or anything but a noobie might not understand what they mean and could get wiped. Plus, I personally think that it'll be good for party set ups and get bonuses if you had a full row (vertical or horizontal).
quick nexus
You've snuck in a second suggestion there at the end which makes this a bit confusing.
Regardless, an explanation of what the classes do isn't really necessary because 1) they say what they do in the title and 2) classes mean basically nothing, there are Attack units with more support than most Support units and Support units with more self damage than most Attack units, so a guide would not provide any broadly useful information.
As for your second suggestion, it just seems a bit random. Why do units need to get a buff when you use multiple of the same type? It seems more like a weird gimmick mode than something that would be good for general combat
Disregard what I said previously because your suggestion is already in the game. Go to "Menu" and then "Help", there's a "How to Play" guide which includes descriptions of what each unit type does. Simple as