HLS: Is Multivariant Playlist loading sequentially by design?

[xCatG]

Hello, I have question about loading multivarant HLS playlist. We currently provide 5 different streams (1 audio, 4 video at different bit rates) served from different hosts, and when observing the loading in a profiler we can see the behavior of

• ParsingLoadable loads the master playlist (determined by inspecting the url)
• followed by loading audio track (since it's listed as the first sub playlist) (again, looking at the url, same for below)
• in parallel, loading the first video track (say 128kbps)
• after playlist of first video track is loaded, the second video track is loaded
• and the 3rd playlist after 2nd is loaded etc

Loading of 2nd, 3rd, 4th playlists are done by different ParsingLoadable, but they run after each other sequentially instead of in parallel which is puzzling. Am I initializing the player/track extractor incorrectly?