Exactly how many aircraft can you provide?
One small bird is not going to out lift the Chinook in the long run unless the haul is very short and the hook up time for the Chinook is slow.
This lifting by the Chinook is not exactly precision lifting but something any reasonably capable pilot can accomplish.
The Longline pilot does it all by himself....while the Military Chinook crew uses a crew member and pilot working together to get the load into the correct position.
I feel you under state the ability of the RAF Chinook crews to do a days work.....though with all of the HSE requirements, planning, briefing, and related administrative hurtles....it would take them a while to actually get to work as compared to the civil operator.
You have a point about using long lines....but then the military (RAF and US Army for sure) do not embrace that technique as a normal role or operational skill.
The military always seems to have a longer lead time and shows up with far larger a support crew than does a comparable civilian operator....been there and did that on both sides of the equation.