The internal links have nothing much to do with ranking. They help in the pagerank/linkjuice flow from within the site.
300 is way too high as it creates issues for the crawler. A figure less than 100 for this is good and acceptable enough.
Apart from manual competition you could also try some free tools like Traffic Travis & Web Ceo for your research. Or you could also use IBP's free version to create individual reports and compare them.
P.S. : By internal links I assume you're referring to the pages within the same domain linked by the page you're competing against.