Got mine today.
To recap the Pikemen box:
It says 30 Pikemen and you get 5 sprues with 6 bodies and 9 heads - BUT you also get a half-size command sprue with bits to make an extra body so 31 in total as far as I can see.
The Zweihanders box has 4 sprues - the same armoured bodies (24) of the pikemen and the same choice of 9 heads. 2 Sprues are straight from the pikemen box, but you get 2 sprues where the pikes are changed for plastic two-handed swords. There are 6 sword arms on each sprue so maximum 12 zweihanders in total.
There are 12 separate metal halberd right arms.
No command sprue.
So you could do 12 and 12 and have 12 pikearms (right) left over BUT you have to use the left arms for the metal halberds - however I suspect some Edition 6 Soldiers of the Empire left arms will work with other plastic bodies one might have
The Missile weapons box has 5 sprues with 6 different bodies (unarmoured) - again 9 heads BUT only 4 of them are the same as on the pikemen and zweihander sprues.
You get 6 crossbows and 6 handguns on each sprue so you can make however many you like up to 30 in total.
No command sprue.
So there is some flexibility with 14 different heads across the sets. I think I am going to do some research on the different 'looks' of Pikemen and Landsknechts.
Warlords say they cover German/Tyrol and Early Swiss on the box, but I also have metal Foundry, Artizan, and even Warlord's ECW plastic pikemen with morion helmets and it may be interesting to see if the heads from that set could be interspersed with these latest Italian Wars ones.
I am also waiting - along with GP - for the figures from a Kickstarter which also come into the reckoning. So I have about 200 figures to sort into appropriate regiments and styles.