Prop Joe, the Greek, and Marlo

I was very surprised that Prop Joe allowed Marlo to meet with the Greeks after the shipment was stolen. I know that he rationalizes it by thinking that the Greeks won’t trust Marlo and would never go behind his back to deal with him, but I have kind of a hard time believeing that wise Joe would trust that enough to basically bet his livelihood and life on it. It seems that Joe would have found another way to satisfy Marlo’s suspicions that the Greeks could have been in on the shipment getting stolen. Or if, and more likely it seems, that Marlo was only using that as an excuse to meet with/get closer to the supplier, then Joe would also realize that was Marlo’s true motivation and at least take the precaution to do the meet in a way that Marlo was alone with him and the Greek and Marlo stayed behind with Joe while the Greek left so that he wouldn’t be able to put a tail on him and find out how to meet him. Joe also could have just told the Greek beforehand that he thinks Marlo is trying to get around Joe to them and to make sure he isn’t followed when leaving. Or at the very least have him tell Marlo something to the affect of “I only deal with Joe, if Joe should die then I will move onto business with another person I know, and if it’s should become a habit that my contacts die then I will simply take my business to another city where I have trusted buyers who want my business.” I mean it seems to me that Joe would have taken at least some precaution to ensure that Marlo doesn’t use meeting with the Greek to cut Joe out and thus have no reason to not kill Joe.