Differences between Tag Class and Promotions Class

[Lonecat Nekophrodite]

1. In addition to XML files assigned to either tables. What else made differences between Tag Class and Promotion Class?
2. When creating new tag class to define changing strengths and weaknesses. If a new class is successor to preexisting and not a combined class (which I creates).
2.1 Is it possible that a unit given a new tag class can share the existing promotion class?
2.2 What are combat calculations when unit of one class attacks enemy units that affected by specific properties of different class when the two are engaged in combat. For example, when Melee attacks Anticavs. How do the game resolves the combat outcome which table or which files did the game, the conditions/constrains ? 'Class/Abilities' file or 'Units' file?
In my mod I've already made a couple of new classes, Infantry, Tanks and Antitanks and modded promotions so to meet with such changes.
Is it still neccessary to mod Tank and Heavy Cavalry class as separate class so to avoid 'Antitank pikes'?

 

[criZp]

Tag class are for unit abilities and promotion class is for what promotion tree they have, they are fully independent of each other

 

[Lonecat Nekophrodite]

So is it possible to loan existing promotion class (and mod convert it) to a new tag class? like Tag Class Tank uses Promotion Class heavy cavalry and mod what promotion does to fit with new class so that with this there will be no 'Antitank pikes and spears'?

 

[criZp]

You can add any promotion class and any tag class to any unit as you wish.

 

[Lonecat Nekophrodite]

You can add any promotion class and any tag class to any unit as you wish.

Two associated tag class can share the same Promo class ?

 

[criZp]

Yes