Aoa,
Dear members... it is being widely adviced to attempt the paper in Urdu, as one can easily include Ashaars, Ahadiths, and Ayaats in Urdu.But dont you guys think that by preparing it in English one has the added leverage.
Added benefits to me are as follow:
i) it aids in enhancing vocab...( i've seen ppl with the GRE books bashing on their heads, so if one is so keen in those ten numbers then why not go about it through the other channel)

ii) as majority is attempting(my assumption) in Urdu , so by attempting in english your competition sphere is shrinked provided you fulfill the requirement of quality i.e inculsion of Ayyats, Ahaades etc

iii) in Essay it would put you in a better position as every year their is an essay regarding islam: war on terror, woman related civilization related( west vs Islam), Islamophobia.

iv) 'CSS is all about english'...if it is anything to go by, then you are definetly getting benefitted( again the added advantage)

If we keep the said points in mind dont you think to opine Islamiyat in English would be a safe bet

Regards