Speaking as a graphic designer - quite a lot of medium sized music companies do this, focus on the product technical design and then the visual design and marketing graphics come second place.
Warwick, lovely looking basses.... look at their website!
Markbass, industry leading position... interesting design choices
Ashdown... brought out the little giant...
But to be fair to them, employing another person with the aim of making the hard to quantify effect they will have must be a no brainer... skip the graphic designer and get it at a lower price point. They either employ someone and either pay big bucks or have someone doing stuff like MarkBass are doing - which isn't bad, it's just not very good, or they use an agency and pay lots of money...