Such splitting is currently not possible in AntennaPod. And I don’t think there’s a true podcasting standard that officially supports ‘two-feeds-in-one’.
Why would it not be usable? You want separate feeds, no? That Podcast Namespace idea allows for grouped but separate feeds.
Indeed if that is implemented the starting point is the opposite: you’d start with separate feeds and bring them together. Whereas now there is just one feed and you’re trying to separate them. But the end result could be the same. If the feed owners take action and support for this would be implemented in AntennaPod (but would be necessary now as well, to do what you want).
It seems you’re describing the current situation, whereas I’m talking about a future situation. When the new system is in place, it is not necessary to have a guid per episode, because they’ll be different feeds.
Here is a proposal for a GUID tag to uniquely identify podcasts with a url derived hash value
This element lives in the <channel> and is used to declare a unique, universal identifier for this podcast.
so it is not suitable for collection feeds as it is on the wrong layer of the tree.