It is unlikely that the DOW armies will return in their old form, perhaps and this is a thin perhaps they will return as a tilean army, with a human focus. For this reasoning I propose as well as many others already stated here that the empire have pikes, and not merely as a 0-1 restricted type of unit. Pikes epitomised infantry combat from the middle of the 15th cent to the end of spear armed troops in the late 17th century, they really were the queen of battle. At their heyday which was during the landesknecht period from 1480- 1550ish the armoured pikeman was what armies were built around. Not handguns not armoured cavalry, not artillery. As these other branches of the army grew better able to deal with rate of fire, or mutated into lighter more modern forms like the carabiners of the Kaiserlicher Ritterknecht the landesknecht period closed and the pikeman was no longer as important.
So in our fantasy version of the Holy Roman Empire is is not unreasonable to want pikes, its also not unreasonable to not have pikes and lots of pistol or handgun armed light cavalry or nearly any variant of handweapon armed soldier, the RW HRE was a fecking huge place with many cultures within it and by all accounts the fantasy version is bigger. So why fight it let the soldiers of the empire of sigmar fight in the manner that seems best to them and build an army list to reflect that. Go for choice.
Pikes as a weapon option for statetroops 3 points from base
this would mean +2 points to an off the shelf spearman=7pts
add heavy armour for 1 point per model=8pts since they cannot have shields
allow this as an elite infantry weapon as well replacing the greatswords greatweapon with pikes for free, -3pts +3pts =same price. Afterall an Emperor from our world fought in a landesknecht pike phalanx why wouldn't KF also fight with that same weapon with his own personal bodyguard.
and there is precedent for full plate pikes in the DOW.
Nuff said for now