Split batch first observations

In an attempt to better my understanding of yeast I split my 10 gallon house amber batch from Sat. They were put into 6.5 gallon glass carboys. One was pitched with Wyeast british ale and the other with Wyeast american ale. No starters were used in an attemt to keep things as equal as possible. Fermentaion lag time was Identical at about 12 housr in , but then the Americans took off and was VERY vigorous, While the Brits just calmy built krausen. The Brits krausen was gone tonight and I took a gravity reading of 1.017. Down from 1.053. Meanwhile the Amricans are still hard at work. Dont think I should even take a gravity reading yet from the Yanks, I dunno. I chilled and drank the Brits thouch, so now Im curious:fro:

I have seen this as well with 1056 and 1098