If Poland has a decent army (which is a matter of political decision) for a country of that size
Russia is not a country of that size. Germany is closer, but it has proven it's capable of building an army strong enough to threaten the world.
Poland is in geopolitical crash zone. Russian Federation wants more land because that's what it does, and also because dominating Poland would give it more sea access and farmable land, something they sorely need. Germany wants more land in the east to control the transport hub Poland is shaping up to be (the new Chinese Silk Road ends here). In World War 2, Poland was strong enough to fight either of them
individually, and it still had experienced soldiers after the 1921 Polish-Russian war. It just
wasn't enough.
Imitating countries like Hungary is foolish, because Hungary is not in a crash zone. It can afford to have smallish military. In case of most conflicts it will be out of the way, just like the landlocked Switzerland it can declare neutrality. Finland was able to declare neutrality in WW2.
Moral of the story: decent army
for a country of that size is not good enough. Poland needs to do better, either through a bigger army or a better army... or diplomacy much better than before WW2, so it never has to fight more than one country at a time. Attacking Czechosłowakia right before WW2 alienated Poland's allies and fueled German propaganda. Suppose Ukraine goes down - there will be voices to capture Lwów, Wilno, etc. That would be a huge can of worms.