Car seats in Toyota 2020 Sienna question

Ma

Why are the anchors in the middle and right side of the 3rd row? I need to put two forward facing car seats back there but they’re too wide to be next to each other. I could switch one to rear facing. Here is my combination of car seats for the sienna:

-2 forward facing car seats

-2 rear facing car seats

Any advice? Thank you!