Thanks @Tylus!
Although once again, most of the credit has to go to the Contrast Paints 
They just make things so easy 
I also just saw a magnetised Eomer on Instagram the other day, so its definitely possible!
Regarding my two Eomers though, here is a quick update:
The models are so detailed, and the white undercoat always shows up the detail really well. I almost don't want to paint them...
Once again, Contrast Paint basecoats went down first. Usually I then finish basecoating with regular paints before leaving the metallic basecoats until last. The armour got a basecoat of leadbelcher, before I then picked out all the red detail (I will admit, not terribly fun
). However, I have Eomer now ready for the wash stage:
The wash has been applied and is now dry, so hopefully I will get to highlight the models and base them today!
I have also picked up my campaign from where I left off and have updated it with the first Two Towers battle report, so check that out if you're interested
They took much longer than anticipated - partly because I was very busy with other things and didn't have much dedicated painting time, and partly because Rohan hero armour is so detailed 
