2U Maths is assumed knowledge for UTS BBus, not a prerequisite. You can get through first year easily without having done 2U maths (Finance is just plugging numbers into formulas and Stats isn't really like HSC Maths). If you choose to major in Finance or Economics, you may struggle at first. Either way, if you work hard you should pick it up. Beyond first year, if you choose not to major in Accounting, Finance or Economics, you will not likely encounter much maths at all.
UTS BBus (ATAR Requirement: 92.50) and Macquarie BCom (ATAR Requirement: 83.60) are pretty much identical. I think the name of the degree comes down to how the uni want to market their product (UTS likes to emphasise how it's degrees are practical and easily applicable to the business world, and as such seeks to differentiate itself from other seemingly homogenous degree products). You can major in all the same things, except I think UTS offers a range of sub-majors that Macquarie perhaps doesn't offer (See here for more information -
http://www.handbook.uts.edu.au/courses/c10026.html). The difference in ATAR requirement is more attributable to demand factors than course difficulty. For UTS, it's City location is a big winner with many people coming from all over Sydney.
Hope this has helped a bit