first of all: Congratulations for getting invited in the first place and of course it is good that you managed to lay out a clear structure for the problem at hand. However, you should always keep in mind that consulting is a people's business. Working on consulting projects, you will have to work with all kinds of personalities, and they want to be engaged and not be confronted with standard solutions. Every problem is different and hence, every solution is, too. Surely, I have not been there in person, but a possible explanation for this feedback may be, that you used the frameworks you learned too strictly.
Thus, I would recommend you to use your case knowledge to lay out a structure as a general guideline and don't fixate on it too much. I haven't come across a problem in real life so far that could easily fit into one or two particular frameworks. Being flexible, adjusting frameworks and issue trees on the go is thus a skill you might work on.