Is it possible to use 2 Arduinos with 3 IBTs to run on SimTools?

My goal is to drive 6 motors to run a 6DOF.
Is it possible to use 2 Arduinos with 3 IBTs to run on SimTools? (Probably this was indirectly answered with a "No," but I could not find that answer)
I attached photos of my setup with the Arduino, IBT and motors.
1) I uploaded the SMC3.ino to each Arduino
2) I tested each Arduino and 3 IBTs/Motors on SMC3 and they functioned appropriately to the assigned USB.
3) I configured the SimTools for each USB 3 and 7
I assumed that SimTools would know the USB assignments and it would magically work. I was wrong. It does not, because the motors are assigned as motor 1, motor 2, & motor 3 for each Arduino and not motor 1, motor 2, motor 3, motor 4, motor 5, and motor 6.
I tested this by using Simtools and LiveForSpeed and only 3 motors would work for Roll, Sway, Surge, etc.

Could I edit the sketch so that there would be motor 4, motor 5, and motor 6 associated to the 2nd Arduino?

Has that already been done? I have looked and tried to find the answers here, but not been successful.
Is it only possible with Thanos, or 3 Arduinos and MotoMonster? If so, do I need to edit the sketch on each of the Arduino to reflect the change in hardware?
Thank you for your insight and experience.

Thank you for your prompt help, also, I corrected a the interface settings.
These motors are attached to two 24V PSU.

So as I understand it, the DOF1 column should look like this? And DOF 2 column should be similar?

Still not turning axis 4a,5a,6a on testing them. It seems that there is no communication between the SimTools and the Arduino on Interface 2, which has 4a, 5a, and 6a. I can tell hear a buzzing noise on the motors when there is data/electricity flowing into them. I will try changing USB assignments.

It seems like Interface 2 does not work at all.

I corrected them as you instructed, but did not upload a picture before. Here is the interface corrections you indicated to me. I even swapped out the Interface assignments for Com 3 and Com 7. So I had Interface 1 assigned to Com 3 which works, and Interface 2 (doesn't work) to Com 7. Then I changed Interface 1 to Com 7, it works. Interface 2 to Com 3 doesn't work. I'm not going to give up. I'm just wondering why it will not drive the motors on Interface 2 (Axis4a, Axis5a, Axis6a).

I actually purchased the full version of SimTools Pro. to determine if it was the problem being a Demo mode version.

Hi, I did a work around. I assigned the Interface 3 to Com 7, with the Axis output to A<Axis1b>][B<Axis2b>][C<Axis3b>. I tested them and it worked. I also assigned different Yaw, Heave, and Surge to these Axis. Whereas, on D<Axis1a>][E<Axis2a>][F<Axis6a>. I don't know why output Axis4a, 5a, 6a does not work on Interface 2 Com7 (Arduino 2). I think the Arduino (2) has the motors coded also as 1, 2, 3 and so SimTools cannot see that as motors 4, 5, 6. Just a theory. Now I am going to mount these motors on the frame and crash myself! LOL,

Did you see my last post regarding "Axis1b,2b,3b" and how I got the other 3 motors to work? As long as the they are assigned Yaw, Heave and Surge separate from the Roll, Pitch and Sway, and they functioning as if they were on Axis4a,5a,6a.

I contacted support from SimTools. The correct settings is this,
Com 3 output [A<Axis1b>][B<Axis2b>][C<Axis3b>]
Com 7 output [A<Axis4b>][B<Axis5b>][C<Axis6b>]

Now all the motors turn as they should.
Thank you for your support

i think you should use 3 arduino for 6 IBT2.
The 3rd IBT in smc3 is 31khz the motor will have noise and whistling while the max frequency of IBT2 is 25khz. i set it to 20khz and Fpid/9 so the motor won't overheat. you can try

I'll give it a go