On these figures it is quite likely that your reasonable needs would be met by a 50/50 division of the capital and pensions so it is hard to see what the justification would be for receiving more of the equity subject to one point. That point is whether your reasonable housing needs can be met for half of £650,000, ie £325,000. The answer is probably yes but property prices vary in different parts of the country so it is impossible to know for sure without further information.
There is also a possible argument for compensation for sacrificing your career to support his. However, that is more difficult to make out and depends on factors such as what career path you would have pursued if you had not moved abroad with him.