After having wrestled with this idea for at least a week, I have finally come up with a solution I genuinely like to the state troops problem, in particular the Halberdier.
At first I approached it from the angle of: what needs fixing? Obviously the halberd does, but working in the parameters of making an army book, we can't change the weapon rules.
Do our state troops in general need fixing? Not really, but they could use a tweak.
There have been a host of good suggestions on the forum, not the least of which is giving halberdiers AP or heavy armour, or a 'step over the fallen' rule. Another popular choice is amalgamating most of the core units.
-The first one is a fix for the weapon itself, not our troops in particular however, so in the spirit of designing our own book, I rejected it.
-The second, heavy armour, is my personal favourite, but then begs the question: all state troops come from the same sprue, so why don't Swordsmen and Spearmen have heavy armour? Certainly none of the models look like they are wearing heavy armour. What's more, there is no justification in the fluff for halberdiers (or any state troopers) wearing heavy armour. Introducing heavy armour is only a good idea in terms of mechanics and game balance then. I will go with heavy armour if no better choice presents itself: I know that there are many equipment and rules choices in Warhammer that don't make perfect sense, and/or don't match fluff and models, but that is not a good reason to select another such choice.
-The third, introducing a special rule like 'step over the fallen' doesn't appeal to me because state troops are supposed to be simple and core. Vanilla. Giving special rules to core human troopers is a precedent I don't want to set.
-Lastly, amalgamating our core infantry into 'militia' and 'state troops' options, with a starting point value of 5 or 4 and allowing players to customize their core choices is an excellent idea, and I also like it quite a bit. It doesn't change the initial problem, which is that halberdiers, unless we pay extra points for them (above and beyond what different units cost) remain sub-par.
It occured to me that it wasn't in fact the halberd that was unbalancing the choice between state troops, but rather the parry bonus mixed with the stat bonuses. What's more, we had two defensive choices, each slightly better than the Halberdier.
This leads me to think that if swordsmen were removed from the picture, inter-army balance would improve. "What?" you say "make the army worse, when we are already flagging behind, just so it is internally balanced? That is non-sense." Which is true: the objective is to tweak the Empire positively, not negatively, in order to keep up with (and slightly behind) the power creep.
So my brilliant idea, such as it is, is to remove swordsmen from the army book entirely, but give their stat bonuses to the other state troops, making them slightly better in their respective roles. -Spearmen, quintessentially defensive, receive the +1 initiative, so that they strike before many other core units of other armies, making them slightly better in subsequent rounds of combat, without dramatically changing them.
-Halberdiers, a generally offensive unit, and also supposed to be the trained, more experienced troops of the Empire get +1 Weapon skill.
-No equipment options change, so each is able to get the handweapon+shield parry bonus if the player wants, but now there is more incentive to use their respective weapons.
I realize that this at first doesn't seem to be a change at all: we can still get swordsmen with a 4+ save and WS4 for 6 points. BUT, they also come with halberds, and lose the I4, which goes to spearmen. With a couple of playtests, however, I think that WS4 S4 will carry the day.
Net result:
Spearmen
Spearman M4 WS3 BS3 S3 T3 A1 I4 W1 Ld7
Seargeant M4 WS3 BS3 S3 T3 A2 I4 W1 Ld7
Equipment: Light Armour, Spear, Hand Weapon
Can purchase shields at +1 pt/model.
Can turn one model into a Musician for +4 points
Can turn one model into a Standard Bearer for +8 points
Can turn one model into a Seargeant for +8 points
State Troops
Halberdiers
Spearman M4 WS4 BS3 S3 T3 A1 I3 W1 Ld7
Seargeant M4 WS4 BS3 S3 T3 A2 I3 W1 Ld7
Equipment: Light Armour, Halberd, Hand Weapon
Can purchase shields at +1 pt/model.
Can turn one model into a Musician for +4 points
Can turn one model into a Standard Bearer for +8 points
Can turn one model into a Seargeant for +8 points
State Troops
Feedback very welcome. Shoot me down!