I'd probably just use dynamic content, but instead of basing it on a profile field like role, I'd use a random number field (populated by the random number math function CC) then I could randomize from the email - who sees which LP & forms, or I could use DC on one LP to randomize the various content - but for testing I'd of course keep it to just one maybe 2 items to test.
But I'd love to hear how others would test Forms & LPs?