I have no clue what his plan was here other than start the Clone wars.
He wanted emergency powers and if he got that by blaming the Sepratists for the assassination how would he get the Clone army from Kamino without looking suspicious like he knew about the army already?
I doubt he told Dooku to hire the Clone template, have him hire someone else, and when they fail have him use a specific dart that is only traceable by a few people. This would align with him picking Obi-Wan and Anakin though, as it would allow him to get in Anakin's mind and drive him to Tatooine, and him possibly knowing Obiwan has contacts that will allow him to get the darts origin figured out. But that is so farfetched so I doubt that was the plan.
So my question really is, what was Palpatine's plan in Attack of the Clones overall?