Mixing various Celestions I wouldn't consider non-traditional or unique. For me, so far some non-traditional mixes that worked very well have been JBL's (D120F's or E120's) mixed with 20w GB's like EVH did, '60's Alnico Blues top row/Fane Crescendo's bottom row and soon I'll try some combos with my Altec 417C's
I'd recommend more guys get outta there box and try incorporating other vintage speakers besides just Celestion's. Celestion's IME have the best midrange, while JBL's and Fane Crescendo's are much stronger in the low end and high end, so the right mix can result in a very complete sound