Hi...Model papers are provided just to give an idea about paper pattern and they can't be used to gauge the difficulty level of a test. So please don't under estimate the test and try to do your 100%.
As most of the public organizations are outsourcing the initial testing and screening to NTS may be that is why SBP is following the same lines.
I don't think there will be any negative marking because NTS don't do so in GAT or NAT tests but you never know so be ready for exceptions.