At this moment we are 4 server developers, 2 web developers, 1 tester, 1 analyst, 1 business ambassador and we're all sat in the same room and thats all there is in there at the moment.
I wouldnt say that we go off in pairs to discuss things after a standup but instead if someone comes across an issue that needs discussing we'll just discuss it. We're never THAT much into the flow so to speak that we cant stop and discuss things however most of the time we just carry on with our own work.
The tester tests tasks as we finish them and we have daily demos of tasks so the tester knows how to use what we've just built. All this has been estimated for as well so the project isn't delayed or anything.
Hope that answers your questions.