Ello Pete!
Not feeling it could mean two things..
One: Your arms are already very well adapted to this movement and it's just because the muscles aren't being challenged.. This is good!
Two: Perhaps you are cheating this movement somhow by only doing a partial contraction and not really going for the full range of motion for that movement...
I wouldn't replace this movement, I would just modify it so it's more challenging..
For instance.. you may not really be engaging your whole torso... I say this because of your "robot" comment, which makes me imagine that you are simply flexing and extending your arms in a limited up down movement.. So it turns out that this seems more like a double handed curl rather than a real shovel action...
Try actually bending your knees as you scoop the snow up from the ground... Don't bend at the low back, just engage your quads and psoas...
I feel that where your gaze goes, your body will follow so remember to always keep them in synch.. otherwise you lose that power and connection to your core and start getting into a potential red zone if you start twisting and flinging that snow willy nilly..
Think that your tailbone is tucked under and keep yourself grounded...
I also imagine that rather than truly pretending you are flinging the snow into a far away snowpile (or you can imagine a coal pile! LOL) you are just bringing the SG into a raised position near your shoulder without much momentum... Try to truly imagine that you are throwing that snow to the side and extend your chi beyond your shoulder as opposed to halting there... Don't get too spastic and abrupt, just let your mind and imagination make it into a more real movement..
I bet that will help....
Engage your whole body.. Don't think "I am a robotronic" whatever..
Think "I am clearing a forty foot long driveway"....
You could also up the speed of your stroke, but would tend not to suggest this because the faster you do a movement the easier it is to become less mindful and hurt yourself...
I'm sure some people will say to choke up less on the handle too.. Meh..
I wouldn't.. Your shoulder could get twinged in a bad way, as this movement is semi twisty... I'd save choking up less on the handle for very simple movements like "flip lever"...
Have a great day!
Peace and Love,
Deb