What ever you want to do with the Entitys and Scene nodes, in this line
enem->setEnemies(enemyVec);
remember that you declared the Nodes and the Entity just in the scope of the loop, and as you didnt made a full copy of them and pasted it into allocated memory, your vector is probably refering to the automatic allocated nodes out of their lifetime and whatever you are going to do with them, its undefined behaviour. So probably some states are still the same in their memory, and Ogre can work with them, but gets errors, because its not exactly that what its supposed to be.
And even if Ogre is handling this, you should notify that
for each
i;j == 3
the initial position is the same. So it could be as refering to the Ogre error, that if pos has anything to do with initialPos, you have non unique strings, where unique strings are expected.