Torosidis played at left back for the Ethniki since he debuted in 2007, long before he ever moved to Roma. He was 22 so I'm not sure your experience argument holds up. Toro was only moved to his natural right back once Rehhagel left and Santos took over post 2010 World Cup.
We don't know if Tsimikas would fail or not at right back, there are challenges with playing on your opposite side as you have correctly pointed out. If JVS is going to insist on Mavrias as the no.2 right back and not consider other options, 10/10 times I would rather see Tsimikas playing on his weak side.