If the i386 build of xerces-c doesn't work on systems without sse2, that is certainly a bug. However, given that this is the first report we've received of this issue, and 16.04 has already been out for 4 years, and support for i386 as a host architecture has been dropped entirely in later releases of Ubuntu, this issue is unlikely to receive attention. I think your internal repository is probably the best option for your issue.
If the i386 build of xerces-c doesn't work on systems without sse2, that is certainly a bug. However, given that this is the first report we've received of this issue, and 16.04 has already been out for 4 years, and support for i386 as a host architecture has been dropped entirely in later releases of Ubuntu, this issue is unlikely to receive attention. I think your internal repository is probably the best option for your issue.