Honestly, there’s not enough volume in the gutter to accommodate that. Imo.
I don’t think there’s an actual solution save for removing the source of the pine needles or a roof over it.
Consider making a little J hook somethin or other on a pole that you can just walk down each side and sweep out the gutters? Or maybe an air tool of similar fashion to blow the needles out. Everyone can use an air compressor if you don’t already have one.
Bigger issue. If the gutters are filling up that quick, the roof is covered with them 24-7.