Station didn't switch to TOO2 by themselves, when you pressed STEP. They where in TOO2, because you finished programing targets on TOO2. If you want to bomb on TOO1, you need to change it on every station.
I belive you answered your question from last sentence in your first sentence - it didn't happend.
And even if that did - programming 8 targets takes much more time than switchng TOO program on 4 stations.