Rolled today and this small dude tried countering my guillotine from the guard by stacking. I didn't sink in the guillotine completely because I wanted to see what he was trying to do and if it works. I assumed he wanted to try to stack and choke me with his shoulder on my neck. Never really saw it come into play because thhe bell rang when he was working it. Is this the proper way to counter a guillotine? If he does stack, what could be done to keep the guillotine? I was thinking off going into half guard and crank from there, or push his hips down and put him back into full guard.