Overall engine and component system health play a major role in cold weather starting success.
In colder weather, you have more things going against you. So the greater amount of things you can get going for you, will certainly speed slow starting complaints.
Valves in need of adjustment are just one of those little things combined with other little problems that will add up to prevent quick starts when cold weather sets in, perhaps not so much noticed in warmer summer temperatures.
If I understand your cold weather starting procedure correctly, success is achieved by pulling towards the front of the tractor on the governor control rod. By doing this you are closing the throttle against governor spring pressure, which you could do from the seat with the speed control lever by pulling it back. Pulling or pushing on the governor rod as long as its not done with force won't hurt a thing.
When the engine is stopped, advancing the speed control forward to the starting position opens the throttle plate. Apparently, your throttle plate needs to be closer to closed for starting, which could be a sign the carburator needs adjustment or serviced.
If your tractor will start in a reasonable amount of time in cold weather (after a few seconds of cranking), with the speed control lever forward just a little or left in the idle position while working the choke, you may have nothing or very little wrong with your tractor. Maybe a little fine tuning here and there will get it to light faster.
As others have mentioned, no two tractors are alike. It may be a matter of simply finding the sweet spot when setting the speed control and working the choke when the weather turns cold.
"HAVE ALL YOUR DELIVERIES MADE BY UNION DRIVERS"