I used to use a SSH bat before short blades were a thing, and remember I had a gun GM Maxi SSH which I dearly miss.
Since short blades arrived, I use a short blade, standard short handle length, so overall bat is 15mm shorter than standard, which works well for me, prob better balance than SSH as hands were a little crowded on the handle for me.
I don't know what the GEM size bats from GN are like in comparison sizewise, and also I think GM had an academy size for those transitioning from Harrow to full size in the past (and also Kookaburra have small mens size, but think the handles are v thin?), whether this is the same as the short blade SH setup.