wuzak
Captain
The reason there was so few of them is because only 300 were ordered, the Spit was the interim fighter until I believe Hawker got the Tornado flying. Someone with more knowledge can correct me on this.
The Tornado and Typhoon were meant to replace the Hurricane and Spitfire.
It wasn't that the Spitfire and Hurricane were "interim" aircraft, moreso that the the Tornado and Typhoon were next generation aircraft.
The war probably sped up deployment of the Typhoon - it may not have been truly ready when it initially entered service.