Every page on your site is a (potential) landing page, with a few exceptions (like terms and conditions pages etc.) all have a prospect of attracting relevant traffic. It sounds to me like you're viewing "content" and "landing pages" as somewhat different entities, which could be a shirt-sighted approach.
Nonetheless, as every page you create is a potential entry page from organic search, you can create as many as you like ;)
If you're creating a series of very similar pages, then if the current batch all operate independently, then you're likely to be able to do so with further pages without risk of triggering duplication filters.
If you think the pages would fail a manual review, then you may be wise to reconsider the approach, and consider how you might target an increasing variety of keywords in a way which cannot create a negative impression.
