This seems realistic. I've guessed that Israel has 14,000 Iron Dome interceptors in the past.
It's believed they have around 10,000 according to this post.
320 David Sling interceptors
200 Arrow interceptors
Which is why US had to deploy Thaad missiles on Israel after Iranian missile response.
Egypt knows more or possibly most about Israel than we'd like to think. Makes sense as if they've historically fought wars with them and Israel is the greatest threat to Egypt.