I couldn't care less about stuff like that really, would people really be happier if they added a minute or two of extra padding between them just to placate peoples need for warp distances? Like Kirk goes to bed and is woke up to be told the Vengenace has caught up to them? Really?!
Btw I don't remember if the Vengeance was ever called by name, Kirk said it was "an unmarked Federation vessel". Also were some lines cut? I don't remember any lines about Starfleet/Federation being about vendettas.