I like the "little and large" partnership if we're going to pretend to play 2 strikers from any era.
The best strike partnership I ever saw was Frannie Lee (92 goals in 139 appearances) and Wyn Davies (66 in 155) Wyn wasn't as prolific but he led the line like a warrior and was superb in the air - proper Welsh salmon (if only BKD was like that these days!)
Frannie's goal ratio over the 8 years he played for us is outstanding, but in mitigation they include a fair few penalties that he got having been tripped somewhere near the halfway line. I swear he could fly! Double the ratio of SJM and in the top flight too.
Sir Nat probably deserves to be ahead of Wyn D - difficult to argue against 255 goals in 452 games - and he'd be a great foil for Lee.
There is also a case for David Jack (144 in 295) but I'd go for Lee & Lofthouse.
Can't imagine why the likes of Bobic could even come into the reckoning. Liked him sure, but he was a loanee that only scored 4 in 15 appearances and 3 of those were in one game.
Lofthouse and Lee were goal machines whichever way you stack it up and would probably have made a great partnership.