What does Qimage do when .... two files are to be printed on one page and one file is srgb and the other is argb?
The simple answer to this is: Qimage is able to process the images correctly.
If you have Qimage set up with Colour Management on, a Monitor and Printer Profile set, the driver set for "No Colour Adjustment" (or equivalent), then the prints and screen views will be Colour Managed according to the profile of each image.
The other condition required is that the image has the profile embedded (preferred) or tagged as part of the Exif data. Or, has been assigned in the Qimage Colour Management set-up window.
In other words, Qimage is "told" what the image profiles are.
Terry.