Ring wraiths vs. Balrogs

[TarElendil]

In Gandalf's conversion with Frodo in the next chapter, he says that "the Riders were dismayed", when seeing an Elf-lord in his rage, so that must mean that an Elf-lord like Glorfindel can scare them. So, although it was the horses who bore them into the water, they were already so terrified, I think they would have rode into the river anyway, also because the Ring-bearer was on the other side.

you cannot correctly make an assumption like that. I doubt they would have rode into the water themselves. It says not even glorfindel and Aragorn could withstand all the Nine at once. Just because they were "dismayed" doesnt mean they woulda jumped in the water OR gotten their asses whooped.