There are two MPHs I work with for this public health organization, and one of them (the one I know better) offered to write me a rec. The two know each other very well. I was wondering if it would be wise to ask them to co-write and co-sign it, because I feel like having two sets of eyes looking at a letter can only make it better. The disadvantage is that, as some of my professors have told me, a co-signed letter is less genuine-sounding, since "I think this student..." becomes "We think this student..." What do you guys think?