In short, I don't really know of any distinctions between the two that are true in all instances. I've actually heard several people assert that anarcho-syndicalism and council communism are essentially the same position.
Yes, I am another believer that they are about the same thing. As you said earlier in your post, Marxists and anarchists did have different perspectives but this has been something that has changed over the years. At this point worker's councils + a state = revolutionary unions that the anarcho-syndicalists want. I'm sure that there are some people that would lecture me on the finer points, but from what I've heard it sounds like the two would be very similar in practice.
“How in the hell could a man enjoy being awakened at 6:30 a.m. by an alarm clock, leap out of bed, dress, force-feed, shit, piss, brush teeth and hair, and fight traffic to get to a place where essentially you made lots of money for somebody else and were asked to be grateful for the opportunity to do so?” Charles Bukowski, Factotum
"In our glorious fight for civil rights, we must guard against being fooled by false slogans, as 'right-to-work.' It provides no 'rights' and no 'works.' Its purpose is to destroy labor unions and the freedom of collective bargaining... We demand this fraud be stopped." MLK
-fka Redbrother