Honestly... The Pheonix upgrade won't do anything because it will cost way too much, and by the time you get the fleet beacon there out with 10 mutas already. Also, if you tech switch to the fleet beacon for that upgrade you'll be behind in every other tech as well, meaning if they just say okay tech switch your in trouble. End of story.
The Pheonix upgrade is honestly a rip off, but that's what I think at least. The only way to fix Muta/Ling vs Toss is to either decrease splash damage or increase storm/Archon damage. But... That's what I think.
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