Silly bus question from someone who hasn't taken our busses

Hey yall. Never taken the bus here before but I'm looking into taking the Fast Gratiot to Downtown next weekend and I'm getting a little confused

So I see the Fast Gratiot route which is on the SMART site as 561, but then I click to view the Route Map and it shows it as 562/563? So that's my first bit of confusion. Is that the same route?

Now, I would need to board at 12 Mile & Gratiot. Does the FAST route stop there? Again on the SMART "Schedules" tab it only shows it having a few stops, but on the route map I linked above it shows 12 Mile as a stop.

So I'm just wondering if my plan of boarding at 12 Mile and getting off Downtown (as close to Grand Circus Park as possible) will work.

Thanks for the help