There is no problem with compatibility or anything. It all comes down to tracking the user if a lot of resources are at disposal. If you are not connected to vpn you are prob not only person in your city on tor. You may be the only person connected to "X" vpn from your city. The first node you hit in your tor circuit can see your IP, but the second node sees the first nodes, and so on. The last node can see the previous nodes ip and where you want to go. This is why its important to run a tor relay when possible. There will be so much traffic your ISP or your VPN will not know if the traffic is coming from you or someone else hitting your node vs a few request a month.
Also I will say that if you want better privacy and want to use a regular browser... setup i2p. Everyone running i2p is an exit node, so if you visit a website you have a 50-50 shot of it being residential ip or it could be routed back through tor or just connected to vpn somewhere. [And thats my 5 post to get that elusive link sharing priv.]