The Comintern did see the occupation of the Ruhr as an opportunity for the KPD to appeal to German nationalism--but definitely not for a merger, let alone a merger under nationalist leadership! Rather, the idea was to attract rank-and-file Nazis and other nationalists to the KPD:
"Nikolai Bukharin publicly, if ironically, thanked French president Raymond Poincare for having disrupted an incipient European stability and in March announced to the Twelfth Parry Congress that the national defense of Germany now had a completely different meaning than in 1914. Moscow discounted warnings by the KPD representative and others concerning what the latter termed the "fascist danger" in Germany.
"One consequence was Karl Radek's "Schlageter speech" to the Comintern executive Committee (ECCI), which declared that the "counterrevolutionary" Karl Schlageter, recently executed by the French for sabotage, should be considered at the same time a hero of the revolution, because supporting the nation in Germany should now be considered a "revolutionary act." Radical German nationalists should be seen by Communists as "erring brothers," not in the sense of political union but with the goal of attracting them to a pro-German Communism (the sort of thing briefly successful in Hungary), once they saw that only revolution would restore the nation. This, after all, was sound Leninist policy, since the now-stricken Soviet leader had always stressed the importance of the national question, which could be resolved only by revolution. Even though Hitler was viewed as a "caricature of Mussolini," many members of the Nazi Party (NSDAP) and other nationalist groups might be won over. Leaders of the KPD, who knew much better the temper and doctrine of German ultranationalists, were more skeptical. As it turned out, the debates with German nationalists that summer in the pages of the KPD's Die Rote Fahne did not feature any Nazi leaders, only a few theorists of the tiny "National Bolshevist" sector of German nationalists, as well as a few "conservative revolutionaries," though Communists addressed several Nazi meetings before Hitler broke off contact..."
https://books.google.com/books?id=zP4ikZ_o3V8C&pg=PA80
In any event, the Comintern, at least from the mid-1920's on, wanted national leaders totally loyal to the CPSU leadership. People showing any streak of independence were purged. Neither Hitler nor the Strassers nor any other NSDAP leader would remotely qualify. Trying to attract "erring brothers" is not the same thing as putting the KPD under their leaders' command...