"The loan was made with the understanding, though not explicitly written, that Company B would, in fact, loan the funds to Company C (except for a 10% margin to be held at all times)."
Like my police friends say to each other, "If you don't write it, it didn't happen." It is VERY hard to prove side agreements even existed or were even enforceable, if there is a written contract
. The chances drop to almost zero if the "bare bones" contract includes a paragraph about it being the "entire agreement". You signed it, you own it.
Loaning to an under-capitalized shell company is inherently fraught with risks which company A will be presumed to be fully aware of.
Generally, if there is any ambiguity (could mean this, OR could mean that) in a contract, the doubt is resolved in favor of the party who did NOT write the contract.
There is also an possible or actual conflict of interest and possibility of at least partial "self-dealing" regarding the roles of Company B's owner as a partial stakeholder in Company C. The entire deal could be challenged as not being at "arms length", and possibly even an attempt to HD&D Company B's creditors even if your charitable heart is giving them the benefit of the doubt. If Company B did NOT retain the 10% margin, there could be a basis to try to pierce the corporate veil and go after the owner personally as well.
And yes, there is probably a very high likelihood that Company B could owe Company A long before Company C repays the loan. Besides due dates and contractual obligations, if Company B is already in breach of the contract, there is the LEGAL obligation coming from and adverse court judgment possible in whatever timeline it takes to prosecute the case and get that judgment.
Location of the companies is usually relevant ONLY to the questions of where do you sue and how do you go GET the money owed. Look to the contracts first, because some include not only "use XYZ law", but "any legal action must be filed [at this place]".