E10 = 9a ?

I was interested to see the grade comparison table on this site. However I wondered if the UK grade of E10 could really be compared to a 9a French grade? Although E10 is probably as hard to climb as a 9a, it doesn't come close as far as technical difficulty. The UK Grade is more a reflection of the route's lack of protection, technically most E10s would fall between 8a+ and 8b+ depending on just how bold they are.