You aren't, there are netting, batching, and matching algorithms that have been developed for larger systems. The Feds, who process $2Tn.+/day, BoE, ECB etc have found these systems to hold up through trials, simulations, and implementations. DTCC, on the other hand, handles $500Bn.

Here's the Fed's review, https://www.newyorkfed.org/medialibrary/media/research/epr/0...

DTCC doth protest too much.