It changes by episode, because Doctor Who continuity is like that. Age of Steel, that's what they say. Cyberwoman, you have semi-converted people with mechanical and organic parts all over.
A bit of a necro, this (but not as much as expected, and less so given the previous last thread post), but I'm catching up on old threads of my interest after an extended absence...
It'll depend a bit on the circumstances. Even ignoring the pre-millenial series (i.e. reboot series onwards, only), in the first (full) appearance of Cybermen (in Pete's universe, in the episodes Rise Of The Cybermen and The Age Of Steel), the first Cybermen (and women) of that type were created by industrial effort and conversion pods, in which all 'useless' bits and pieces of the body were removed and replaced with a cybernetic chassis as per the method that their creator had developed.
By the time of the Battle Of Canary Wharf (Army Of Ghosts and Doomsday) the Pete's Universe Cybermen who had established themselves (albeit with resistance, by Humanity, by the likes of Rose and Ricky!Micky) had part-assembled their own conversion equipment that was necessarily less bulky and probably consisted of local resources (the non-Pete 'standard' universe).
As this is also where the Torchwood 'Cyberwoman' came from, we can see something of what was (partially) done, even though in the Doctor Who episode it was largely obscured by plastic sheeting. I think we can assume that was an interrupted conversion.
It's arguable whether the episode The Next Doctor even feature Pete's Universe cybers (but actual Mondas ones, in a weird parallel development... the kind that originally made the 'classic' Cyberman head that was found in the hidden museum in the episode 'Dalek'), because all of Pete's Cybermen should have been drawn into the Void. And then there's their possession of the historic record of the Doctor that the clearly Mondas cybers would have been encountering.
But word-of-God suggests these
were Cybus Industries cybers, who then (defeated) went and mixed with the Mondas clan and inspired aesthetic/practical redevelopments of the cyberspecies that the reboot-series continues to employ in future encounters.
However, whoever these Victorian London cybers are, they appear to have had whatever form of ability to convert into full Cybermen deprecated by having been stripped of their usual equipment, and the basic lack of local technology to replace it... They're basically making do (see also the non-cyber examples of Mme. Pompadour ship systems that went for a clockwork/bio-acquisition solution when things went wrong, and their sister ship's equivalent decisions in Breathe). And without the Cybercontroller their capabilities seem limited to cyber-creatures and cyber-controlled humans (a lesser version of the 'earpiece hijacking' technology that appeared on Pete's World) and shear force of will over ordinary children until (they hope!) they can bring about the rise of their surrogate walking dreadnought technology and bring the mind of their main human collaborator into the collective.
Certainly it seems that Eleven (Pandorica, Closing Time and, especially, Nightmare In Silver) is dealing with Mondasian cybermen, as does Rory (when he's trying to track down Amy, in full on Roman Legionary mode, as he cuts like butter through the cyber-armada to deliver the question and the message for A Good Man Goes To War). Nightmare In Silver shows that a properly established Cyber-colony now has technology somewhat similar to the Trek universe's Borg nanobot conversion, although Pandorica suggested that (re-)assimilation by a biologically-extinct Cyber-unit can also be undertaken by the mechanical head alone establishing a new 'host' (or, perhaps better, a new 'guest') consisting of just the head.
When Twelve eventually encounters
his Cybermen, we (actually before we are actually aware of it) are shown that a full Cyberman body retains only bones beneath the metal shell (although presumably there'd be brain beneath the skull, and thus maybe marrow within the bones, but the Dark Water itself shows that no other obvious organic matter exists above those bones). But even this method could have been kick-started by nano-infection.
So there
are discrepancies (among which are the question of why sometimes they employ the rat-sized Cybermats, the insect-sized Cybermites or possible dog/cat-derived Cybershades as their more mobile 'helpers' while they're still working away in the shadows and/or underground), but you
could explain it by local circumstances (especially the energy and resources available) and the amount/type of link they have to their cyber-forebears...
But for this DF mod, you could definitely pick any single version. According to taste and/or what suits the modability of the game. I don't think there's a 'wrong' way of doing it. It can easily be something not-quite-canon and yet entirely fit how the Cyberrace would work if it got chucked through the Time Vortex and landed on the DF world.
edit: And I've just remembered the "Wooden Cybermen" that appeared at the very end of Eleven's tenure as Doctor. Although that wasn't so much "lack of resources" as the need to overcome the standing defences/detectors of the place the Doctor was currently protecting.