The job looks like its as per the drawing, the drawing and calcs must have been done by a designer, I presume the designer is qualified , I was told at scaffold school the designer was always right.
That said I know different designers have different ideas about beams ,Alwyn Richards does a very good course . Be good to hear the view of any design engineers on here though
You'll be lucky to get designers to give an open forthright opinion on their competitors schemes. They all seem happy to criticise others work when touting for your business. Although they stop well short of cleaning up their own profession & outing the incompetent companies amidst their ranks.