1. 7
2. 16 (or 15) and 9
3. 9 (or 4), 2, 16 (or 15).
The 2 is the bomb! It's kinda in a class by itself and therefore challenging to put into categories. However, you just have to have one and, in that regard, it doesn't count as 1 of 1, 1 of 2 or 1 of 3 - it just is. You gotta have one, it doesn't count so you can have the 2 and still have 1, 2 or 3 in addition. Though the Machax is cool - and you also have to have one of them, it does overlap functionality to a good degree with the 9. Folk with disagree as to which is more versatile as between the 9 and the 4 but if you're thinking along the lines of wood prep, either will do just dandy.
I am a big fan of the 15 along with its big brother the 5. Both, especially the latter, excel at food prep and other slicing/dicing tasks. The 15 is also very capable in dressing and skinning game but do have to admit that the 16 hits the sweet spot (Sweet 16?) for bushcraft, game chores and general purpose afield.
Then there are the little ones - the 11 and the 14/24s. Sure their functionality is to some degree duplicate the performance of a folder but they are so much more (and stronger!) ... you just gotta have one or more of them as well.
Hopefully I have sufficiently muddied the otherwise clear waters of your question and complicated through pontification your simple and succinct interrogatory.
Hey, it's what I do!
