yeah, they would go to sleep, but they wouldn't sleep very long, usually just 45 min because they weren't tired enough. but 4 hours should be long enough...
you could try walk in walk out, as DD gets older it seems to be what works best (and really less stressful for us too). she can't seem to settle and go to sleep if we are in there with her. put him down for bed and leave. if he cries, go in and comfort until he stops, then walk out. when he starts crying again go back in. make sure you are only responding to true crying, not mantra crying. i usually stop and count to 10 before going in too because even if it's a true cry sometimes she will stop and settle herself.