If the lower middle order includes Rashid, Swann, Broad and a wicket-keeper (all credible no 7 bats) then quite what order they take strikes me as of no great significance.... but if you look at Rashid's season... he's surely done enough to be a credible no 6 bat:
Code:
Yorkshire 2007 - LV County Championship - Division One
Name M I NO R HS Avge 100 50 Ct St
J A Rudolph 15 22 3 1078 220 56.73 4 3 19 0
Younus Khan 13 19 2 824 217* 48.47 3 0 11 0
A McGrath 14 22 2 931 188* 46.55 3 6 11 0
A U Rashid 15 21 4 790 108 46.47 1 7 8 0
Rashid held his own in comparison with Younis Khan... one of the most successful Test batsmen in the world (with a Test average of 48.98).
In fact, Rashid contributed significantly on 8 occasions out of 21.... which is far more than his illustrious international colleague managed... and is actually more than star-man Rudolph managed: unlike so many in county cricket... his average is NOT inflated by one or two absurdly large scores.
Bottom line: he already offers at least as much with the bat as the up and coming Andrew Flintoff did when he toured India (and batted at 6) in 2001/02.