Tried different versions of Dism on the windows 10 computer by copying the Dism folder and dism.exe and running but it still failed.
Checked the version of winpe that Landesk 9.6 SP3 uses and it was 5.1. Tried then to inject instead of the windows 10 nic, the windows 8.1 nic driver using dism but it still failed.
Went back to Landesk, Manage Drivers in Winpe image, and inserted the win 8.1 nic driver and it worked.
I'd still like to know why Dism doesn't work if anyone can comment on that.