I'll keep on with my rant.
We're talking here about a concrete case, if there are no raws for a chapter (and you can't find it searching the web) and the English scanlation doesn't allow it to be used.
I wouldn't like to be the international scanlator in one of those cases, but sadly, it does happen, and what you should do is ask them nicely to allow you to use their raws or their scans, explaining the reasons and that stuff. If they don't reply or they say no (I don't think they say no if you explained nicely, unless they're heartless scanlators who just do it for internet fame), you can't use their scanlations, or at least can't post it here.
But what you can actually do is (unless the translation isn't allowed to retranslate to other languages, which happens in very rare cases) linking to the English release to that chapter and making a translation, so that that language readers can read the manga just like we do with raws before scanlations are out.
I get that this could be a legal issue that might effect the site and why you wont allow it here. But if this this is about crying over some credits for something that you don't have the right to... I don't think "you" deserve it. If this is about copyrights of a scanlator then that's just plain silly. And if you're not allowing international scanlations just because of a make-believe copyright then that's even sillier.
Again: Yes, the English groups don't have permission from the mangaka either but that doesn't mean that they're not worth the credits. That you* take their scans for your second hand release is only proof that you profit from their work too, so why being cocky about it? If they didn't provide you with the base, how would you release?
Copyright and legal claims aside, we see it as simple matter of politeness to listen to the requests of the people who make manga available for your enjoyment. These requests are the only thing they can do to control the spreading and quality of the releases in favor of the original author. That has nothing to do with 'scanlator copyright' at all.
Don't use the 'wild wild internet' as an excuse to drift the whole thing into the bottom corner of illegality. It's free, so I take it without second thought? Go into reallife and try it with a car, if you feel this way. It's people like you who give the bad light to file sharer and similar communities. Those who always take everything for granted because it's not touchable, not affecting your reality. It's you and only you who thinks that politeness and care have no place in (semi-)illegal fan communities.
All we ask of you is to be polite towards the people you feed on. Be it the original author or those who provide you with everything you need to release. If you lack these little basic social skills, you're simply not welcome here. Thread is closed for too much flaming.
*With 'you' I talk to those who feel addressed and not to anyone personally in particular.