Stalin was "re" arming long before Hitler even came to power. In 1932 for example the Soviets produced more tanks then Germany in 1940.
Noone was aware what was happening in the USSR anyways. So no - France and Britain will only rearm if they have an agressive Germany - in this ATL they have a far less agressive Germany - meaning that they rearm far less - and are far weaker then OTL.
You know one day people around here will begin to get the idea I am obsessed with maps, with climate and topography, with road and rail and port capacities and the such like. The USSR just like modern Russia have a legitimate case for having one of the world's largest if not the largest ground forces. There is a very simple fact that The region occupied by the USSR has long land frontiers and that the main avenues of threat are widely separated and not easily accessed from a central reserve.
However yes the Soviet tank output was impressive, yet their supply of tank transporters was rather less so, this meant that their mechanised forces were not equipped properly for long strategic moves or long range advances. In fact logistics in general was a relative weakness of the Red Army throughout its existence.
This however was not because Soviet planners were incompetent. The Red Army had a doctrine, that was it was going to fight as much of its campaigns as possible in the near abroad. It was not designed to try and conquer Europe by main force, the kind of resources in trucks and horse drawn transport that would require were beyond Soviet capacities.
Beside which the Soviets including Stalin were largely of the opinion that they did not need to embark on campaigns of conquest. They simply wished to ensure the territorial integrity of the Soviet Union and the ongoing control of the Communist regime.
Also there was extensive monitoring of Soviet activities by Western intelligence services, they never caught everything, no service on any side caught everything but they were aware of general trends such as major re-armaments programs.
No they will not - see my first post
Also you are comparing 1932 to 1942. I would suggest you compare force levels in 1940 - when the Western Allies were at war and the Soviets still at peace
You can shout and yell and flap your wings till all your feathers fall out but it will not change the fact that Britain and France will be able to call upon allies, even in the event of Germany going communist they will be able to rely on most of the nations of Europe plus very likely large swathes of the German elite and armed forces to oppose the Soviets be they German or Russian. In addition there is the looming presence of America which just as it risked war to protect a market in China will certainly provide aid short of war in order to protect its markets in Europe from communism.
Then the Soviets must also consider Japan, a nation noted for its designs on their far east territories. Yes Japan's ground army is not very modern but it is large and aggressive and its naval forces and air forces are also large and modern.
Further but assuming your "Hi I am high on crack" Stalin tries to invade Europe then France and Britain
and their allies do not need to match the Soviets man for man as they will have the advantage of being on the defensive. Worse even for the Soviets even the USSR is not a complete autarky and will experience issues with a blockade...not enough to bring the regime down by itself I would suspect but enough to make war making very much more arduous and less effective.
In addition but the Soviet armed forces are less than likely to enter any conflict in a state of high efficiency due to the ongoing purges carried out by Stalin...if the man could not resist a purge when confronted with genuine (Hitler) and perceived (Post WW2 Western powers) existential threat then he will not be able to resist when time is on his side. Purging was just compulsive behaviour in the Stalin regime, it was too much part of the instruments of power he employed.