The G12 City's handles are now shorter, just like the classic city, meaning you cant wear them by the handles on the shoulder anymore. Sorry to say... I have big arms too and can only fit the older and longer handles over my shoulder, too.
The new G12 PT has handles like the older longer ggh PT handles, but thinner. It looks like you can still wear the G12 PT handles on your shoulder. At least this is what I've noticed.