Dealing with duplication

I suppose I am like many wargamers I buy figures because I like them, the "Ooo shiney" syndrome which when added to the I "need" a couple of those to finish off the army - "Mission creep".

I have a number of completed DBA armies - Greek, Persian, Thracian, Roman and Macedonian (and a couple of unpainted - Celtic and Carthagian). These can be morphed into HoTT armies as I have a number of bases of creatures from mythology. So this is all well and good.

To be honest the anicents aren't really the problem - HoTT armies are. I have accumulated 2 orc armies using Ral Partha miniatures. These figures can easily be used to fight Greeks or Romans etc. 

This is the Warband Army.

Made up of 3 Riders, 2 Shooters, 5 Warbands (including the general) and 4 Hordes (or Spears if I want to buff the army a bit).

This is the Blade Army. 

Made up of 2 Riders, 2 Shooters, 4 Blades (including the general) and 5 Hordes (or Spears). There is also the Orc Warmachine as artillery - not pictured. 

Then there are these 2 (effectively orc) Lord of the Rings armies. 

Angmar

Made up of the Witchking (either a Hero or Knight general), 2 Riders, 2 Beasts, 4 Warbands (including a general) 1 Behemoth and 4 Hordes.

Mordor

Made up of a Nazgul (either a Hero or Knight general), 1 Riders, 2 Spears, 3 Blades (including a general) 1 Behemoth and 8 Hordes.

There is also a 2nd Age Elf army - and recently I completed the Numenor/Early Gondor Cavalry. Plus Wood Elf, Rohan and Haradrim in very unpainted states in a box. The above discussion doesn't even to bring in the Warhammer Elf and Hobgoblin armies for even more duplication. 

The bottom line is that I don't need to store this many armies .... My current thinking is to sell off the Lord of the Rings stuff, perhaps keeping some for skirmishing ....

Any suggestions about the duplication dilemma would be appreciated.