What is this non-sense of raising his profile? Basically, playing with Murray will make his name known to less serious tennis fans. How does it matter? He is not running for a public office to be worried about how many people know his name.
He won career grand slam in doubles with Nicolas Mahut (yes, they together won all four majors). If at all he is playing doubles, he should actually work with such an established partnership. Besides, Mahut likes grass also.
Unlike in some other majors, in Wimbledon doubles is a serious business. All men's doubles matches are best of five right from the first round. Nobody even knows, whether Murray can hold up if the match becomes a long-winded affair. The situation was even more uncertain when Herbert accepted (as at that time nobody knew whether Andy would hold up in 3 set doubles as well).