That's how other exchanges do (my local exchanges too), almost the same address for all of the users but with a different tag.
If your main concern is the sending of xrp without tag, most of the time it doesn't work, an error will show that the tag is required. Also, xrp users will probably won't forget that very important thing sending xrp.
The same address with different tags means that the wallet is controlled by one company that's how your local exchange works
Here it is clear that 2 casinos use the same wallet and the same company address it means that they are interconnected, either through third parties or other services. The most sensitive part in any company is funds so it doesn't make sense to me when the wallet can be controlled by a third party.