I was asked a few weeks ago for some size comparison shots of the Allarus Custodes, so while you can't see them in the picture above, they are in the pictures below
These shots give you some view of the scale creep, what I needed to include here was a Tactical Marine to complete this view, although all my tacticals are on 32mm bases so do look that little bit bigger.
Below you can see a Custodian Guard & Allarus Custodian side by side, the Allaraus model is a little bulkier than the Custodian Guardian, but I dont think he is that much taller - his plume helps but head to head its about the same.
A quick snap of non Custodes sizes - for references (if you need it), left to right its:
Kharadron Arknaught - Sniper Scout - Intercessor - Cataphrattci Terminator - Captain in Gravis Armour - Roboute Guilliman - Mortis Contemptor Dreadnought
Anything else you would like to see in a size comparison here, let me know and I will see what I can do!