In this analogy, the needle
is as big as we can make it.
Gas-rich is where the danger is, as I understand it. Those gasses expand as they get closer to the surface, and if they're trapped in viscous magma that doesn't flow easily and puts a lot of stress on the rocks above.
The fluid basaltic lavas of Hawaii don't explode, they flow out and make shield volcanos.
Check out geologist Shawn Wilsey's videos.