I'm not familiar with SD recorders, and have only taken a brief look at the manual for the 744T just now. So the following comment may be out of place, and if so I apologize already--but: With potentiometers--physical, continuously variable resistors, as opposed to discrete gain switches or digital gain controls with preset values--the best you can do is calibrate a "pot" at one or two points in its range of settings.
No potentiometer has an absolutely predictable resistance value at all points along its range, so there's no such thing as a ganged set of potentiometers that maintain matched resistance throughout their ranges with zero tolerance. Deviations are par for the course. They can definitely be audible where a stereo image is concerned; our ears and brains are far more sensitive to mismatches between channels than they are to nonlinearities within a given channel.
If your application requires fraction-of-a-dB control over the gain relationship among channels (e.g. acoustical measurement, Ambisonics/SoundField or double-M/S recording), you can't depend on ganged analog potentiometers to track one another closely enough. It's not in the nature of the beast. You'll need to use test tones to set and match (hmm, where's "game"?) the exact gain for each channel, either during setup or during post.
What I gather the 744 most likely has is dual, concentric potentiometers behind each of the front panel controls, and the way that they're employed in the circuit then depends on a switch setting. But that's two (!) ganged pairs of electrically and physically separate potentiometers. In the relationships among channels controlled by "pots", the worst-case tolerances can very well add up (e.g. the gain set by one pot may be 1 dB lower than its scale indicates, while the gain for the pot on another channel may be 1 dB higher than its scale value, for a total of 2 dB difference, etc.).
Also, depending on the circuit and the "taper" of the pot, the tolerances can very well be wider at one end of the scale, often the lower-gain end (the attached photo shows the gain pots on a Nagra IV-S, which could be ganged via a little clutch on the red part of the left pot; these were very high-quality pots costing more than an entire recorder might cost today, but they had all the problems that I've mentioned).
--best regards