Suit issues with brother and best man. Freaking out

We told our gentlemen back during January what suit and where. We've told them of multiple sales. We found a brand from JCP from the j f ferrar collection and now we are running out of sizes for my brother who's a groomsman. All 3 have dragged their feet but the other 2 are at least pretty normal in sizes. Our date is 6/27 and because hes big chested and shouldered were running out of options. He is a 46 chest and there is only 1 in that size but a super slim. The slim and classic are both out of stock for his size. My mom is worried it may be too tight. My fiance has his already. Theres a sale going on till tomorrow night where the suits are 85% off. My mom and brother are trying to tell me "well I found another suit in grey". Are my fiance and i being selfish? We already bought his suit which will match the boys and we don't want to have 1/4 guys even slightly mismatched. Once again I've told my brother for several months now to GO IN AND GET FITTED! Jcp is closed due to covid19 so he can't even just walk in and see how it fits. Now were bout 3 months away and I'm freaking out 😟😖😓

I've told my mom that she should go ahead and buy the pants and maybe the super slim and see how it fits. Is this a good idea or no? Jcp said they will extend any warranties to 30 days after they reopen stores so they could exchange it later.
I just got off the phone with her and she was supposed to call me today and tell me what was going on and show me the other suit. She didnt call me sonic had to call her. She ordered the other suit without showing us. I've yet to hear is the best man ordered his