Archenemy? They barely interacted with each other. Morgan Elsbeth was closer to being her archnemesis than Baylan because at least they have history.

That history was not expanded on that much. Besides, Mando season 2 feels like they just met. Baylon is more familiar with Ahsoka, as he is with Anakin. Baylon did use his words to bring Ahsoka down a peg in their first fight.

The same can be said for Baylan and Ahsoka, their history isn't expanded either and they never met before the events of Ahsoka.

But he did strike her on an emotional level, something Morgan has NOT done.

Like, no he didn't. His apprentice had more history with Ahsoka than Baylan and did more to hurt Ahsoka emotionally than Baylan.

How exactly? Injuring Sabine doesn't count, as Ahsoka arrived in time to give Sabine the treatment she needed. Skoll accused Ahsoka of abaondoning Anakin, which brought back Ahsoka's memory of that vision on Lothal. She may have kept a pokerface, but it did effect her on the inside. She was able to recover after her lesson with Anakin on the WBW however. There might be more in the next season. Skoll is likely going to be more dangerous than Morgan too.

How is that enough to make him Ahsoka's archnemesis? And her being affected by Baylan's words isn't even explored enough to make him archnemesis worthy. In fact, Baylan knowing about Anakin being Darth Vader is a massive plot hole as Palpatine made sure no one knew his true identity. So him accusing Ahsoka of abandoning Anakin makes no sense.