I don't quite follow what you mean by "miss-match". I think you might be confusing wattage with resistance.Just to be clear, are you saying that in one 40 watt SR, he would have had at least 4 200 watt speakers(possibly more if using 300w JBLs), totalling 800 watts or more? That seems like quite the mis-match?
You can use any high wattage speaker with any guitar amp. There is no need to match wattage rating to amp wattage. in fact, if you run a 50watt speaker with a 50watt rated amp, you will probably blow the speaker since amps produce more actual wattage then their rating (long story why...)
Ohms (or resistance) is what is important to match. A 2ohm super reverb transformer wants to see 2ohms. This means FOUR 8ohm speakers wired in parallel. Or an 8ohm vibroverb transformer wants to see a single 8ohm speaker (or in the case of SRV, he used 4ohm bassman transformers in his vibroverbs which DID cause a missmatch... a big part of his sound IMO)
I ran a 67 super reverb into a quad of 300watt EVM-10M speakers (thats 1200 rated watts) for 5 years of gigging. Amazing sound. Eliminating ANY speaker distortion gives MUCH better sound from my point of view.