Well yes exactly, gerrymandering is about using "geography" as an excuse to rearrange geographic boundaries to change proportions of ideological grouping.
Those quotes are doing a
lot of work, though.
If the original boundaries were established by using handy waterways and watersheds as limits between township groupings ("everything west of the main creek and east of the ridge, as far downstream as the minor creek from the western dale") then that might look a bit jiggly because of the geography/geology being a bit jiggly. The township that grows up about the main creek, both sides, might be on the main portage route into the next area and make a well-appointed trading town that spans the originally conceived district boundary, the mining camps/towns up the side-valley may boom and bust as various factors require and at times vastly outnumber the main-creek dragstrip area. There are socio-geographical reasons for shifting boundaries as relative fortunes change, when it's not clear why houses on opposite sides of a fordable creek aren't in the same zone, or why settlements part way up on opposite shoulders of the ridgeline
are.
But if it looks like you threw darts blindfold at a pre-cut patchwork quilt and chose to 'connect' small bits (including enclaving, exclaving and corner-touching-at-best membership of the larger pattern) according to just which ones you like the look of once you peek again, then you're probably dealing with random "geography" such as "the eastern fence of old McMurphy's cornfield, cut through the Maple View estate on the line of the old drove-road, head for the pine stand above the old quarry, round the quarry, back to the drove road, back down that road except for a bit of the meadow where McMurphy used to graze his cows before they eventually built the grainstore there (now a retail park), across the road up to the old Van Der Waal estate cum retirement chalet community, then straight back down the same avenue (now lined with warehouses,
not included in this zone), and anothe bulge to exclude the old duckpond..."
That's not how it's justified, but how it ends up. Physical geography is meaningless except by coincidental accident or as a remnant of a now irrelevent stakeholding that used possibly long-obscured features to define its extent. Social geography is perhaps a cause, but equally likely an effect. And when you reboundary areas to dilute and strengthen elective powers you're necessarily putting people who don't 'belong' in with people they don't even fit with, just as an excuse to (dis)empower one or other grouping.
What maybe is needed is an Algorithm. Use it to completely re(re)zone areas to some suitably minimum boundary-length-to-area ratio, lowest combined RMS-persondistance from the central point of the respective area, equal(ish) population, etc. Perhaps prefer (but not rely upon) watercourse/watershed/highway/etc boundaries (TBD) with only NS/EW joins between such stretches that don't otherwise connect. Run it five times in front of various allied party observers from outside the area with only physical cues (physical geography, basic population information but not density and definitely not voting trends) and take suggestions as to how to re-weight the parameters, until they are all happy it's not likely to go crazy, then run it a sixth time in front of the local officials "for real", to reveal the new political map that they'll have to work with.