If I understand you correctly, you are asking for the following changes:
• Create a new issue #280, move all existing info including cover scan from #280/A to #280
• Move all existing info including cover scan from #280/B to #280/A
• Move all existing info including cover scan from #280/C to #280/B
• Remove #280/C
The problem with that is that somebody who has (for example) the Potocki cover in their inventory will end up having a database that says that they have the Mozchops cover in their inventory. Similarly, somebody who owns the English cover will end up with a database that says they have the Potocki cover in their inventory.
It might be one thing if the contents page of #280 assigned A, B, and C variants to these covers and CB has them mixed up. But they simply list the covers without letters, so what CB has isn't contradictory. And, for what it's worth, CB lists the three variant covers in the same order as the contents page of #280.