Your link didn't work for me, but your point is probably somewhat valid.
It seems likely the Germans could have overwhelmed the Czechs in the summer of 1938. On the other hand, intangibles might play a role.
Was the German military really as ready for war then as Hitler implied? Or might a tenacious defense by the Czechs have produced results similar to those between the Soviets and Finns in 1939?
Pure numbers don't always tell the whole story.
The Germans in 1938 had a very good army.
The Soviets in 1939 had a really bad army. About 90% of their higher officers had just been murdered by Stalin, and the remainder were for obvious reasons scared to death of doing anything that might show a spark of initiative.
Even assuming the Czechs were as good as the Finns, which is pretty unlikely, I don’t see any way they could have duplicated their resistance. Even the Finns had to submit once General Winter was no longer in play.
The Czechs also had the problem that 25% of the total population of the country was on the other side. 1/3 of population of the Czech lands was German, and about 90% of the area in which any fighting would actually take place.