Looking good! Don't compare to other houses. We had two in our estate that started about a month or two before us. We will move in before both of them!!! And one with our same supervisor started a week after us yet moved in a week before us.
They are all their own build with own issues so you might gain time later in the build.
Ours from site scraping to handover is 40 weeks. With 39 rain days claimed I think from memory so pretty much 8 weeks of work with no penalty. To tell you the truth I'd be surprised if you would be done in 20 weeks even without the brick delay
Good luck - let's hope you gain some speed the next few weeks!
Building Majestic 40 - wisdom homes