Yup. I've shoved bits of a PlayStation game inside a Linux MIPS program and I've made a native port of a Linux x86 program to Windows, all without source code, decompiling anything or even fully reverse-engineering said bits. The toolchains happened to agree on calling conventions and structure padding/alignment, so it was mostly a matter of writing shims to glue everything together.

I don't have the tooling to meld together incompatible ABIs. I tried once with two really similar ABIs (MIPS PIC and non-PIC) and while I've managed to work around incompatibilities with assembly trampolines, the debugging experience was so poor that I rage quit. Never tried with different CPUs.

I'm crazy enough to think it ought to be possible (there's plenty of prior art for most of the needed pieces), but I'm already stuck inside a rabbit hole so deep I can't see the bottom... I'll let someone else investigate that.