Board Thread:Lore Discussion/@comment-3539474-20130910213054/@comment-17114085-20130919132946

The thing is High Rock's Climate is very similar to Skyrim's, a little less cold though. This will make extended invasion costly(supply wise) and they will need to have supplies coming from the sea every so often.

One thing i think you forgot to add to your scenarios is the Nords, they absolutly hate the AD and will be the first to jump on the "lets kill those damn elves" boat, so High Rock, who has infact received requests from the Stormcloaks for an alliance, receive reinforcements much faster, and without the need for the Empire to bring it's Legions from Cyrodiil.

If they go for your Invade High Rock first plan i think it may go down like this:

High Rock: 250 AD vs. 300 Empire(initial AD victory)

later Stormcloak reinforcements around 500-Human victory

Cyrodiil: 750 AD vs. 1000 Empire(as they didn't need to send reinforcements to High Rock)

Imperial Victory, but at heavy losses, as Cyrodill is the easiest to invade and adapt in.

This is why i don't think it would be wise to split their forces, as they are outnumbered and the Stormcloaks will help the other humans as they HATE the AD. Also one thing that the AD has to their advantage is the WGC which lets the Thalmor stay in Imperial provinces, and cripple them from the inside out, this is why Stormcloak victory in Skyrim is better for the humans in the upcoming Great War.