I love John Eaves' D4 battlecruiser (the K't'inga refit) but that Thunderchild is just plain ugly. If you were wanting an escort retrofit, why not do something cool like the Steamrunner class, why take a great design (Alex Jaeger's Akira class) and mess it up and make it fugly?
Same can about be said of the Excelsior...yet we have Excelsiors still in use in-game. They could rebuild these ships from scratch, or the silhouette of these ships with new technology. I would say that canon in this game has been ***** to the point where this issue just shouldnt matter anymore.
It's called modular construction, and it's already provided for in the game lore. Read the Path to 2409.