I think you'll find many big memorials have addenda for the people either discovered belatedy to have died, or those who DID die late, of wounds, influenza, etc. They might be men killed in Ireland. They might also be men originally from the area whose military links to Leicestershire are slight. My mate researching men from Southend, Rochford and the locale, is still finding people who moved away whose only family remained local - so their names are recorded.
You'll know from surfing there is a website for the Missing, meaning people who are in the wrong graves or have incorrect commemorations because of badly transcribed (or wrong) IWGC/graves registration cards.
Polygon Wood looks good from the air. I thought it to be one of the gloomiest and saddest places I've visited. It also has very big rabbits!
MB