I might also add that I would prefer to NOT have to add a switch. The ASR1002 has multiple available interfaces that I would like to utilize. Many of these interfaces need to share the same gateway.
The ASR1000 gigabitethernet interfaces are not switch ports, they are routed ports. You have the wrong platform if that is your intent.
The ISRg2 to my knowledge supports switchports as it supports ethernet switch modules. I do not know enough to speak to the limitations of that platform however.