You can buy the 2.0 compact in a 3.6" barrel and theres a link below that compares the two. Personally the shield is not a good pocket pistol and the Compact of a better IWB pistol so How about you figuring out it the slightly larger and 8oz heavy compact 2.0 is worth owning for YOU. Both make a 4" version too

I have a 4" 2.0 compact OR and TS ready that may be a carry option one day but for me I still carry a full size LW Commander in 45acp and I have a 15 shot 4.24 m&p 40sw handgun while I carry both in a MTAC iwb holster 3:00 . If I need a smaller pistol we have a old m&p9c and a kimber ultra 9mm . Maybe my wifes p365xl with a wilson grip module , maybe . Not a shield .