Just came upon
Hints on Shooting and Hunting Game; Life Experience of Frederick H. Erb, Jr.He demonstrates the low gun style of Live Bird shooting "20 years ago" (written in 1904) contrasted with the post-1900 pre-mounted position
https://archive.org/stream/howtotraindogsca00erbf#page/46/mode/2up 
And we were, and are, all different. Ready positions at the 1896 GAH at Live Birds; some standing straight, some with an exaggerated forward lean, most in-between
What most certainly will NOT work is to try to alternate between doubles with significantly different dimensions. Pick a mount style, and dimensions that work for you, and stick with them.
And BTW: back in my younger days I would stop shooting trap at least 2 mths before bird season and only shoot low gun skeet, with my (one) quail and pheasant gun.
