It would be a different mechanic as Dark knight can turn on Darkside while in grit and the warrior has a 10s cooldown in his switches. The paladin is supposed to be the sword AND shield of the people not the sword or shield. if we could swap stances on the fly it would give us more resource management options instead of just being a complete TP drainer and it would make fights much more then just FB->SB->RA spamming in between damage mitigation and the other OGCD skills. it would also be much easier to implement instead of having to tweak the whole tool kit and watch for what would need to be balanced afterwards in every skill.