Goff had 3,700 passing yards to WRs and TEs, and his group was St. Brown, Williams, LaPorta, Patrick, Raymond, and Wright, so your 3,550 to WR/TEs checks out.
I was a little extra optimistic and had him throwing for 4K to WR/TEs and about 450 to everyone else. My thinking was the top 6 pass catchers are so good, that there is almost no point to target anyone else. However, I am probably downplaying a guy like Zaccheaus, who has had 500 receiving yards in 2 out of the last 3 seasons. So that would also contribute into that 4K to WR/TEs.