When you already defined Agile as a mindset, as stated in the article, the alternatives are simply Waterfall or the combination of both. If you lay out different ways to implement Agile as an alternative to Agile, you're defining Agile as a method or worse, a methodology. So, IMHO, some people might read this and see the contradiction. Probably instead of "... alternatives to Agile", "... ways to implement Agile" is more suitable for the title.