Edit: I believe 275/65x16 front tires are a bit too big for use with 44" diameter rears. The machine will have too much front "lead" in 4wd.
The attached chart is from the U.S.
L2850 WSM. For farm tires the 7-16 size for fronts (about 28" dia) are paired with 12.4-24 rears (about 45" dia). This shows that the intended front/back tire rpm ratio for the
l2850 4wd gearing is about 1.6 to 1, assuming normal front-pull about 5%.
For turf tires the chart's 355/80-20 rears (44" diameter)
are paired with 212/80-15 fronts (28.4" dia) - giving an rpm ratio of 1.54 to 1, slightly more front-pull than with farm tires.
The 275/65x16 tires you list above are about 30" diamater so with 44" rears the rpm ratio is 1.47 to 1 - meaning nearly 10% front pull. Might be goofy going down the road. It's not a huge difference - and could be made up by airing up the rears and letting some air out in front - you could experiment to see what works best in your situation.
You may already know this - U.S. R1 farm tires are typically 85% as tall from the bead as they are wide - but the 85 is not included in the designation. Instead, its just 12.4-24 with the 85 assumed. Metric sizes state the inflated width in mm, height % of width, and inch rim size. (ex: 355/80-20, 212/80-15, etc.)
Hope this is useful info. Sorry for all the edits. Dick B.