Possible issue: Disparity with Living Dead and tank max HP

[Seraphor]

That's fair. Lightspeed in that rotation could feasibly be moved to after the Swiftcast + Benefic II for better effect, and a Benefic II put in Lightspeed's position.

I would cut the Swiftcast entirely, Lightspeed lasts the duration of Walking Dead, and likely Living Dead before it too.
You might need it for a raise if you fail.