That is most awkward. I know someone who had a similar issue and it didn't end well, they called off the wedding and split a few months later!
He had his mom and brother and SIL and 2 nephews and his nan. (mom's mom.) Also his dad's mom and dad. (So 8 in total.)
She had 5 sisters and a brother, the 5 BILS and the SIL, and a total of 11 nephews and nieces, and then both sets of grandparents, and 3 aunts and 6 cousins and their partners and kids.
His parents families had lost touch with most family some 10 years before he was born, so his entire family was just his mom (dad died when he was 6,) and his brother. (And the SIL and their kids.) And 3 grandparents. Both parents were 'only' children, so he had no aunts, uncles, or cousins.
Basically, SHE had over 50 people to invite, (and that was excluding friends and colleagues,) and he had less than 10. He was proper bummed out about it, and kicked off and said she can only invite 10 too.
Went down very badly. As he was THAT controlling so early on, she called off he wedding, and they split shortly after.
No idea what to suggest OP, but the husband-to-be sounds very controlling already (to me anyway.) 'No you may NOT invite more people than me.' 
Men who have behaved like this before the wedding, often get pissy and offended when their wife starts to become more successful than them, and starts to earn more.
Some men are just so insecure that they can't bear their woman being more successful or more popular than them, and yeah, they can't even stand them having a bigger family. He is basically jealous. An ugly trait. I would have to reconsider marrying this man.