Who pays their assistant more than they get paid themselves?

I ask because according to Bruno Waterfield in the Telegraph not only do over 1000 EU staff earn more than the PM, but,

there are 19 European Parliament assistants, or researchers to MEPs, who earn £75,752 a year.

Which is very odd as the MEPs themselves are on, 84,000 Euro which on current exchange is about £70,000.

Would be fascinating who these 19 are, and why the MEPs in question think that they are so good at their job that they should indeed be the MEP.

I wonder how many are family members?