I've been using this as my default Sputtertube strat all along, and it has always worked perfectly.
Now, the first time I use it in 8.3, it fails in a very specific way: the Squirrel does not survive to an Undead round to Stampede. I reckon this is actually the correct behaviour for Corpse Explosion, much like Failsafe should not kick in for Explode. I wonder whether Blizzard fixed this as a bug.
Tested 3 times, but I'd be happy to hear others' experiences, just in case my brain was not in gear. (edited)
Forest Sproutling has the same abilities; using 1-2-2,. I put the Sun Sproutling in the 3rd spot, just to play with Fist of the Fores] - it was my first time playing with these pets. I really like doing battles that use pets I have but no one uses in their strats. Thanks! It was fun.