Engineer goby in 45gl?

[clk17]

I was told by the guys at my lfs that i cant have an engineer in my 45gl because they get to big.

Now is that the case?
Would it work if he was the only fish?
Currently i have
2blue spot cloud damsels
1 bangaii cardinal
And my strawberry pseudochromis just died for some reason. (Everyone else is healthy so im not sure why)

If i found the other fishies homes and had the engineer and corals would that work?

Anyone?

 

[Dmorty217]

The LFS is right they get 12" , that would look pretty silly in a 45g