The Breen series could (and IMHO should) be shuffled around pre-Cardassian front. There have been a number of player requests for this.
I could definitely agree with that. I think the Breen series should be available much earlier ... however, with it's current place in the episode list, putting the 2800 before it doesn't currently make sense.
good point with the breen series already happening as far as the ambassador is concerned. for feds the breen series should proboly be between the romulan and cardasian arcs then. and the old drake mission should proboly be inserted in the klingon arc.