"2 mpp trackers" Don't connect those together.
Each tracker has terminals to wire up 2 parallel strings.
425 or 455 watt 72 cell panels should be wired in 2 strings on the separate trackers. That does require 4 conductors from the array(s) to the inverter. The Q-cells 425 watt panel has a VMP of 41.2 volts and IMP of 10.32 amps. The VOC is 49.13 volts. With a 500 volt peak input, figure we need at least 25% safety margin because you said it gets vey cold. So 375 volts at 25C to be safe. 375 / 49.13 = 7.6 means 7 panels in series. 7 panels at VMP = 288 volts x IMP = 2976 watts. If you put that on both trackers, you get just under 6,000 watts.
I found the GSL web page describing this inverter, and it does show a block diagram with the 2 + 2 solar inputs and the battery input all going to a common DC bus in front of the inverter block. I can't find any mention of specs for over paneling this unit. The fact that each MPPT tracker input is rated at 18 amps, seems to me, that is the maximum current those inputs should ever see. And here is how I came to that conclusion.
7.6 kw of inverter capacity
Maximum charge rate 190 amps, with a voltage range of 40 to 60 volts. 7,600 / 190 = 40 volts. The current probably has to ramp down as the voltage climbs to stay at 7,600 watts
18 amp MPPT input up to 425 volts. 18 x 425 = 7,650 watts in for EACH of the two trackers. That is up to 200% solar input power. It will most likely limit down to the 7,600 watts. The chosen panels are not the best match to maximize this inverter's solar inputs. Putting 2 strings of the Q-cells panels on one MPPT input would be a waste of the panels. 14 x 425 watts should be up to 5,950 watts. But even if it only goes into current limiting, and does not damage the MPPT input, it holds it down to 18 amps, and we still only have 288 volts. 18 x 288 = 5,184 so you lose almost the full output of 2 panels. If you put 7 on each MPPT input, then you get the full power of 5,950 watts to the DC bus.
Why do I get the feeling this is another Deye 8K inverter? All the specs match the Sol-Ark 8 K as well.