No, as we have learnt from our experience, higher numbers don't mean they are better.
In your case the Radeon 9200 is better than the 9250
Since the 9250 has a max bandwidth of 64bit and the 9200 has a max bandwidth of 128bits.
Concluding that the 9250 is inferior when it comes to CPU to GPU calculations per second than the 9200 which allows twice as much data to be sent and received between the CPU and GPU.
yup, the 10 Mhz does make a little difference in old games, it also gives you higher headroom to OC a card.
But the cards are basically the same if I was to compare it to day to day life, it's like getting hot water to make a cup of tea and the other being cold water to make a cup of tea. With one I can make tea faster since it's already hot whereas the other one is going to take a minute longer.
Well like a game called Doom 3 it says it needs a Radeon 9200 but will a 9250 work perfectly fine? Or is it still better to get the 9200? Will it make a noticeable difference having the 9200 or 9250 for Doom 3 or The Sims 2?