With that in mind, I understand the release of the Napoleonic Wars as an exclusive Multiplayer Expansion for Mount and Blade. Though I don't understand the point of releasing With Fire and Sword. From my own point of view, this was supposed to be the upgrade version of Warband's Single Player Campaign but it seems it didn't do well.
It wasn't supposed to be an upgrade of Warband.
WFaS was developed, in Polish, at the same time Warband was being developed, and as such it was based on the original M&B. A game was released in E. Europe based on this development. SiCh, the developers of WFaS then ported it to Warband and released that game in E. Europe. Finally, Taleworlds and Paradox got involved to translate it to English and release it internationally. That was the release you know that happened last May. It wasn't until a patch of this release mid-summer last year that they actually updated the engine to include the new battle orders and behaviors that has made WFaS what it is today.
For more info see: http://forums.taleworlds.com/index.php/topic,210530.msg5074236.html#msg5074236