The Grand Tour alignment was less about being able to visit the outer planets, and more about being able to do it cheaply. One spacecraft was able to visit four

The Grand Tour alignment was less about being able to visit the outer planets, and more about being able to do it cheaply. One spacecraft was able to visit four planets! That's rare! If you're willing to launch four different probes to visit those four planets, it's not trivial to do, but it's not hard. (Jupiter's position basically sets your launch windows.) And just hurling something out into the black as fast as possible pretty much is trivial. If you can round up the money for the spacecraft.