OK, limited the system memory to 512MB and tried again. No errors and the install seemed to go fine.
Unluckily the install is broken, it did not update config.sys and did not unpack one DLL,
[C:\wpos2]wpos2
SYS1804: The system cannot find the file OS2SHCWP.
The DLLs are in C:\wpcos2 and in there I see OS2SHCWP._LL. Hmm renamed it to OS2SHCWP.DLL and WordPerfect started, asked for a license number with text saying it will run fine but the number is needed to later update and pressing enter, WP started fine.
To work around the lack of DLLs being found I entered,
[C:\wpos2]set BEGINLIBPATH=c:\wpcos2
[C:\wpos2]wpos2.exe
OS/2 uses the kernel directive LIBPATH to search for DLLs, could have edited config.sys and added c:\wpcos2 to the LIBPATH statement which at one point was the only way to do it. Now a days we have the environment variables BEGINLIBPATH and ENDLIBPATH to add directories to the LIBPATH.
If I was interested in using WP regularly, I would create a wpos2.cmd file containing the above statements and create a program object pointing to the cmd file.
eg
@echo off
set BEGINLIBPATH=c:\wpcos2
wpos2.exe
and put wpos2.cmd in c:\wpos2.
So in summary, you have too much memory. Unluckily you have no easy way to decrease it. Maybe running lots of stuff would allow it or removing some of the SIMMS to have less memory. Here ArcaOS includes an updated os2ldr and a utility, memlimit.exe allowing to limit the memory seen by the system. Unluckily can't share them due to license.
Edit: I assume that limiting your memory to 2GB would be good enough to install WP