Clarification: CL X-ships, though they require X-points to be fielded, do not count as Capital ships for the purpose of Fleeting.
CL X-ships may escort DN, BCH, and CA X-ships.
CA X-ships DO count as capital ships for the purpose of fleeting.
This was never specified and was debated with the RMs. 2 of 3 agreed with this
Until Advanced Era rolls around in Y2293, X-ships are supposed to be rare items otherwise the game balance is thrown out of whack. Basically, when making dyna rules, you need to bump up by 2 classes any given X-ships in Late Era to get their true impact on the game. This means any CL-class X-ship should be classifed as a BCH, any CA-class X-ship should be classified as a DN, any BCH-class X-ship is definitely a BB-class ship. Only when you are looking a DD-class X-ships and below can you safely not account for them in fleeting rules.
In other words, all those CL-class X-ships and above should have been treated as min. BCHs which mean under the fleeting rule used in earlier eras in AoTK2, no fleeting was allowed. Otherwise, the game balance is definitely not SFB late era in nature. It's more Advanced era and beyond to SFC3-style eras.
The only time you can start loosening up for X-ships and start the super-cheese fest fleeting wise is in Advanced Era where all those Middle Era and Late Era non-X-ships are gone from the shiplist.
Let's follow the SFB stream of the game on this issue like we do in other eras, not fight against the SFB stream and cause angst among a lot of players. I never saw any mention that AoTK2 was gonna be an Advanced Era play in Late Era dyna cuz it's supposed to end in Y2286, not Y2296. Cuz Advanced Era game is what you have now.