I notice that several informations are driven by the pining class :

• ability to shoot out of CC with shorter class (optional rule)
  
• movement type (infantry, vehicle, ...) and interaction with terrain
  
• ability to pin same or less class
  
• special damage table for superheavy/praetorian/titan

The skimmer ability mixes with the pining and the allowed movements, and also permit pop-up attacks.

The floaters/fliers have differents pining rules, different movement rule, and are generally vehicles.

Those rules have more and more exceptions :

• Chaos greater demons move like infantry but pin like knight.
  
• Squat Goliath Megacannon pin like vehicle but use the superheavy table
  
• Some version of the Necron Monolith moves like skimmer but can't do pop-up attacks
  
• The Chaos Skylok is both a flier and a titan
  
• The Ork MegaSquiggoth is a Superheavy but do not use the damage table
  
• The Ork BlastaBomba is a flier and a Superheavy
  
• The Chaos plague tower is even more complicated...

So I splitted the followind informations :

• movement type : Infantry/Cavalry/Vehicle/...
  
• Pining class : from 1 to 5, or 1+ to 5+ for skimmer
  
• I added the "Superheavy", "Floater", "Flier" and "Pop-up attack" abilities for the damage table and other special rules.

This is more clear and takes less room on the army cards.

Do you have a better clarification of these points ?