Honestly, if you wanted to maximize population expansion rate and you were hand-selecting the crew, you'd send 100% female and cryopreserved female embryos. You'd choose women with small stature to maximize how many you can send / keep alive with a give payload mass, and ideally from families/cultures that tend to have large numbers of children starting at a young age.
In practice, of course, there are other factors beyond maximizing reproduction. Particularly if the people going are paying customers rather than people being selected by some external organization.
I'd think that, considering the risks, a single failure in power and all the frozen embryos will die. The advantage of sending adults who produce their own gametes is that, as long as a single couple survives, he will produce unlimited gametes for the duration of his lifespan (barring exposure to radioactivity or solar flares or whatever the hell exists in the harsh environment) and she can produce a single child a year.
Whats more, using adults as containers for gametes gives you automatic protection and defense of those gametes. The freezer containing embryos will not even be able to identify danger, much less retreat from it.