Try this easy exercise at home. Get an object (I'll use a pen) and hold it with both hands. Ask yourself two questions:
1. What am I holding in my left hand? (A pen)
2. What am I holding in my right hand? (A pen)
Each end of said pen probably has some different attributes...such as you can use the ball point end to write on paper with and the other end might have the clicker thing to extend/retract the ball point, BUT at the end of the day you're still holding a pen. Those differing attributes do not change the object you are holding into something else. How you hold something does not change the nature of the object itself,
only in how you can use it.
Can you use a pen if you're holding it with both hands to write on paper? Well maybe, but it will be pretty awkward since it's designed to be used with one hand.
Pretend you own an urgosh:
1. What am I holding in my left hand? (An urgosh)
2. What am I holding in my right hand? (An urgosh)
The same can be said of a Staff. You can hold it with one or two hands and all that really changes is how it can be used. Your basic premise seems to be this:
- I'm wielding a quarterstaff with both hands (Staff Fighting).
- Each end of said quarterstaff has some stats associated with it (d8 damage, "Staff" weapon group, etc.)
- These properties "create" a new "Staff" weapon group item.
- Said item can't be a quarterstaff because it creates an infinite loop so it must be some "new" item that belongs to the "Staff" weapon group.
- A "Staff implement" is always treated as a quarterstaff, therefore neither end of said quarterstaff can be an implement.
- This also explains why you believe that while all staff implements are "Staff" weapons, not all "Staff" weapons are implements because of your "newly" manufactured "Staff" weapon group item.
Does that about hit it on the head for your position?
And quite frankly, doesn't my example above show you exactly how silly that position is?
The problem with this logic is with the line I highlighted. No new "weapon" is created. The game is describing the (weapon) mechanics that apply to both ends of said "item" be it a pen, or an urgosh, or a quarterstaff. For purposes of an implement I don't care about what weapon properties the staff has, only that I am now "wielding it in each hand".