This is about the noise floor. What you lose when you go from a fully balanced Preamp to a SE amp is common mode noise rejection. The signal is sent normally and inverted in a balanced unit. Any commonality between those two signals is rejected which is why balanced gear is so quiet. It is also why it is so expensive because the entire circuit is doubled.
With the ARC you are paying a lot for something you aren’t taking advantage of and it won’t be at its very best. It is up to you if it is worth the added cost.