I decided to purchase another Broadcom card as it seemed extremely unlikely I could get 3 defective in a row, which would rule out the card being the issue itself. Low and behold, it kind of worked. Once I installed it and booted into Windows 10, wifi settings were enabled and it started searching for networks, however once it found them and tried to connect it kept disconnecting. Upon looking at the wifi adapter in the settings I could see the adapter switching between enabled/connected to not connected. I tried adjusting the seating of the wifi card and antenna, but it continues to have issues remaining active for more than a few seconds. I then switched to Yosemite and strangely enough working flawlessly, no disconnect, perfectly fine. I then decided to switch the broadcom card for the one that was not working previously and rebooted into Yosemite to see its also working flawlessly. The only conclusion I can come to is that once Windows detected the Broadcom card, it transferred the driver information for Yosemite to run it. This similarly occurs with Thunderbolt devices. If I plug them in and boot into Windows then Yosemite, they mount. However if I go straight into Yosemite they will not show up at all. Something is clearly still off on the Windows side. Any ideas on how to get a stable connection there? Im going to try and see if there are any driver updates that might help.
As for why the new broadcom card got it working in Mac OS even though both cards work now, the reason actually comes down to the screw that holds the card down. Apparently if you screw it all the way down, the card or seating disconnects from the board. I left the screw out while testing the new card for easy removal if it didnt work, and luckily stumbled onto what was causing the issue to begin with...