See topic #18325 for a precedent.
In the Sekaiju no Meikyuu series, each class has four portraits to choose from. Although the portrait chosen for a character has no gameplay bearing, they are different appearance-wise. Despite being visually unrelated to the point of being entirely distinct character, we have only one character tag for each class. However, unlike in 7th Dragon, these portraits do not have official, canon, or default names (unless you want to argue that Mediko and Sensei are official, which they're not). I'd propose having tags for each portrait such as medic (sekaiju) 2 or medic 2 (sekaiju).