I'll try to get a similar list together as above for overall version for the armor kits now... it's actually less complicated than the above list might imply.
Mine protection:
Simple, because there is only one kit. It's used on the A6M, A6M CAN, Strv 122B and PSO, and might be used for the Leo UrbOps (i doubt it).
Turret top add-on armour:
For top protection, there are exactly two upgrade kits - Strv 122 and A6 EX/E/HEL, however both are related (in an evolutionary fashion - to the point that the A6 EX originally mounted the same kit as Strv 122).
Afaik, the older Strv 122 kit is considerably heavier.
Turret side add-on armour:
For side protection of the turret, there is only one kit, exclusively used on the PSO demonstrator. The UrbOps will likely receive some additional side protection derived from this.
Turret front add-on armour:
There are only two basic add-on kits for the turret front - A5 and Pz 87 WE. A5 adds the well-known wedge shape on the front, the Pz 87 WE upgrade basically bolts titanium plates over the already redesigned turret front of the Pz 87. The A5 frontal wedge kit is used by all A5 and A6 versions including Strv 122.
The A6M CAN also adds a slat armour cage around the turret to provide some stand-off protection against HEAT jets.
Skirt armour:
Exists essentially in the old A4 variant, a somewhat better-armoured (newer) variant used on all A5/A6 models, and a heavily armoured variant on the PSO.
The two standard variants only extend over the forward two roadwheels, i.e. along the glacis. The PSO variant extends over the forward five roadwheels, i.e. also the crew compartment (but not the engine).
Hull add-on armour:
Add-on kit versions: (A6 EX/E/HEL / Strv 122 / A5 DK), A6M CAN, PSO / UrbOps. See below.
All other versions have basic A4 protection level on the hull (with some differences in crewspace protection, ie. liner etc), that includes German/Dutch A5 and A6 versions as well as the Swiss Pz 87 WE upgrade.
- The Strv 122 add-on essentially consists of a MEXAS-H kit bolted on the forward hull, including a redesign of the entire frontal hull. The upgrade used with the A5 DK as well as the one for A6 EX/E/HEL is also
very similar to this, and externally looks identical to the MEXAS-H kit. Essentially, this is the same add-on kit, but evolving over the space of 10 years.
- The A6M CAN kit has a very distinct look, consisting essentially of armor plates bolted straight onto the basic A6M glacis. No other redesign features hull-armour-wise, which gives the kit a distinct "add-on look" btw, as opposed to the more integrated upgrade above.
- The PSO kit is also not related to the above MEXAS-H kit. There's no additional armour added to the glacis in this upgrade at all, instead the upgrade focusses on protecting other potentially weak points - rear side - against primarily asymmetric threats.
As an aside, there are already certain differences within this "basic A4 hull protection" stemming from the age of the particular hull mostly, or rather the batch in which it was produced - with newer batches, improved composite armour was used; in some of the above upgrades, the old armour was then also replaced by improved composite armour.
As a general notion, one can consider the basic A5/A6 hull to have somewhat improved armour in comparison to a "typical" A4 due to this - but this only stems from improvement to the armour structure, not from a rearrangement of armour or variation of thickness etc in any way.
