Neither Drilled nor a free reform is turning this into 40K these rules exist in the warhammer historical rules and denote a difference between professional and feudal, warband, or militia armies. The same difference as exists between empire and the other races in fantasy. The elves as long lived and swift acting as they are, are still essentially a militia army which is why their rules are they way they are. Chaos likewise as with all the other races they all have their special characteristics. A suite of rules added to the detachment set or state troops set would be in character and in tradition for warhammer in general.
I agree with adding pikes as a new weapon option but it would not materially change the fragility or general use of the state troops, likewise heavy armour for most unit types wouldn't change much. Nor would changing their character profile be fluffy they need to still be basic men, not superheroes but men with training. Changing their psychology, training profiles would however affect their play styles a great deal and that is more in my opinion what is needed, essentially a revamp of the detachment/state troops system. Looking to the warhammer historical books for references is in my opinion a very good way to see what wheels have been tried in the past and determine, so to speak, which set we'd like to try on for the revamp of the state troops in the empire army.