That's why there is something called "Stall Breaker", stall is really easy to counter if you know how to do it. Watch some tournament matches for Top PvP players and you will see. There are many Stall Breaker such as :
Attacker :
- Heracross Jolly guts flame orb (Close combat / Stone Edge / Megahorn)
- Diggerbys jolly/adamant choice band (Frustration / Wild charge / Knock off)
- Staraptor jolly/adamant choice band (Brave bird / Close combat)
- Darmanitan Jolly/adamant choice band (Flare Blizt / Supperpower / Earthquake)
- Slaking jolly/adamant choice band (Giga impact / fire punch / ice punch)
- Dragonite adamant choice band (thunder punch / extreme speed / Outrage)
..........
Special Attacker :
- Kingdra modest ss choice specs (Hydro pumb rain / Draco meteor)
- Nidoking naive Sheer force life orb (Ice Beam / Flamethrower / Sludge wave / Supperpower)
- Dragonite rash weakness policy (Hurricane / Outrage / extreme speed / dragon dance)
- Latios timid life orb (Calm mind / Psyshock / draco meteor / roost)
........................
You dont have to be afraid of chansey or blissey, if your pokemon has bulky move or psyshock then itsnot a big problem.