In a recent game, I used Saruman in a formation consisting of three companies of uruk-hai warriors. Assuming all three companies are side by side in a straight line, I know he has to be in the middle company. However, am I allowed to move him around within this company during the movement phase? This came up because if I swapped Saruman with the uruk-hai next to him so he was one space to the right, he'd be in tremor range of two enemy formations rather than only one (spell range is measured from the caster so his exact position matters).
Seeing as heroes are able to jump between formations across the battlefield, swapping places with the guy next to him doesn't seem unreasonable (as long as the hero remains in the middle company of a formation obviously). After all, a hero is always where he needs to be.
So what do you guys think of this? Is this just a clever use of positioning or is it cheating/an exploit in the rules? Or perhaps I missed something in the rules and they state the hero must stay in exactly the same place they were in when they joined the formation.