The Front half looks much more organic than the back, and It seems more detailed.
@Estoc It is - that is the aesthetic difference between them. Of course, part of the lack of detail in the rear is the style of the two kits; the rear one is a very old Airfix kit (I think it was designed before the designer of the front part had been born!) and it "works" by adding detail parts on to it. The front half is a GW kit and the main structure is basically four pieces that jigsaw together in a way impossible without computer design!
The curved elements of the front part should be repeated as detailing on the rear, I think.
I think it's the double driver view ports that jar a little. I'd consider removing the top front section of the rear half altogether and replace it with something that blends in organically with the front. And which ideally gives you a bit more room to pose figures inside!
This early in the build it looks like two things smashed together. Some greebles will add detail, interesting textures, and bits and will help the back half match the front better. It's got legs (well, wheel and treads), though. I can see it becoming something cool!
I agree with@Benjamin Hayward . Adding fuel cans, tools,stowage bags,etc will help the back half look as detailed as the front. The additional viewports work for me but I can see where they may not work for others.
Perfect ork truk, oh, wait you want it for space french, hmmm, @Grumpy Gnome and @Benjamin Hayward
Have the right idea about adding greenables (packs, armored plates, etc.), the double driver view ports are actually not a real problem as it would likely still look like a composit (I would just flow with it and say its a made in the field vehicle and focus on making sure it looks nice part wise with no obvous seems). I would just add front mount gun or something to the veiw ports, give them an excuse for being there, but that’s me.
I am not sure if I don't need to remove all of the rear section above the mudguards and then rebuild / replace the whole of the bodywork. Right now the main issues (as I see it) are the twin view ports and the angled shape of the rear compartment. That would remove both of those - although what I would replace them with is another matter.
@Danforth Laertes I like it, I think that it works very well, what I think it needs, is the front GW machines roof, should be raised to meet the hight of the rear. Then a T piece griding could be created. The cicular window would be deaper and if you wish a curved "Knights visor" effect could be lowered like the WW2 American halftrack. Then finish with racks and storage. I think its great the raising makes it all one vehicle.
@Geoff Maybury That is an interesting idea - I hadn't considered raising the front up (because it is already fairly high and to raise it would make the vehicle less streamlined). But it's an interesting option....
Someone on another forum suggested an idea that came to me independently while they were making it; slice off the top of the rear section and put some railings on it. This ties in with the overall "railings" look of the Genestealer vehicles. Mockup shown.
@Danforth Laertes Thats not bad, depends on your aproach to the rear, if shes to be a solid top, with open troop firring stations or WW2 style of open top . You could make a ball turret for the side ring. Arm pit, ball roller deoderents are great. Lifting eyes could be put on the rear sides, and at the angle, to go with the wing front items. Then visually weight wise, it constantly becomes one machine. What ever is your choise you have nailed the over all concept.