Do the values listed at the team-selection screen list the modifiers for the soldiers you have, or just the orientation of the military doctrine that team uses? In other words, will my Norman knights have the offense value stated, or will it be modified by some type of bonus?
The firepower upgrade for your team should be one of the first upgrades, not the last. You don't get enough time to really enjoy that boost to your pistol, and so far in the game your pistol is really underpowered, and not worth investing in.