What's wrong is that you may have been in too much of a hurry to notice details. This ain't a track meet! Take it slow and easy, JM, and you'll learn some Greek. (-;
See if you can answer these questions about the sentence:
1. What does ἐὰν mean? How is it different from εἰ ?
2. Why is φθάσωσι subjunctive? (Don't confuse φθάνω with λανθάνω!)
3. What does τοι mean?
4. Did you look up ῥᾴδιον ? (Don't confuse it with ῥήτωρ!)
5. What is the number and case of βαρβάρων ?
6. When you see the article τὸ with an infinitive (in this case, ὑπακούειν), what does it mean?
7. Does the verb ὑπακούω have more than one meaning? And how about παραμένω ?
8. When you can't find a main verb in a sentence, what verb do you always know is missing?
Take your time with your answers, JM; use your book, your memory, and our previous conversations here at Translatum, and you'll be well on your way to understanding this sentence!