Badpickey gear:
Fuji S2/S3/S5 Pro
Kenko MC7 2X, Pro 300
Nkkor 50 1.8 70-300VR
Phoenix 100, 650-1300& Sima 100mm F2 SF
Sigma 12-24, 18-50 HSM, 18-125, 50-500, 70-300, 120-300, 1.4X 2x
Tamron 28-75
Hi, you also have overlap:
The 3 sigma's 12-24 18-50hsm and 18-125 overlap each other in the 18-50 mm range (right?)
same with the tamron 28-75 wich overlaps the sigma 18-50 hsm and the 18-125 (right?)
you have nicely summed up my gear to sort of the camera , but i use on the F 65 for 90 % the 28-80 from nikon the rest of the lenses are mainly used on the D50 and the D70.
to comeback at your question so a 28-80 and a 28-105 added to 2 28-200 lenses. there is a lot of duplication going on here. does the 28-105 have that much of a different look to the 28-80?
yes it does , first of all the 28-80 is silver and the 28-105 is a black lens .. and about the duplication between the tamron 28-200 and the sigma 28-200 is maily caused by the lens creep of the sigma , .
first the body question i see 3 body's (right?) you must be cloned

2x

(but that also effets mee

)
is there a difference in resolution of format ?
i see one VR lens on your sig and that is the 70-300 right?
well i don't know how stable your hands are and how much you use the low end let's say from 18-70 mm dx perhaps the best optin would be the 16-85 vr that will replace the 12-24 sigma and the 18-50 hsm (those could be sold than) the 18-70 dx ed could also be an option , it is one of mine favorite lenses because it has good optics and feels solid and is solid and it would fit perfect with the 70-300 vr (than you could sell the 12-24+18-50+28-75 ) the only problem is that the 18-70 from nikon has no vr so you almost automatically come up with the 16-85 vr witch is the more high end version from the 18-55vr and the 18-70 dx ed (witch you don't have but could be a alternative lens..
Thanks for the time and effort you took.