I doubt very much that Odin has typical business motivations. Odin must be worth billions so he simply can't have simple business/profit maximization objectives. I only see Odin renting out his Valkyrie to a Denarian if and only while that Denarian is personally working against the Outsiders and maybe only if to a Denarian who is working with - or are a member of - the Grey Council. Marcone may fall within those qualifications given his actions in Battle Ground and his position under the Accords. But he would appear to be a singular exception; no other Denarian showed up to oppose the Titan and her allies.
I would also suspect that if Gard stays with Marcone, she would also continue providing Odin with intelligence. Maybe that's enough of a reason for Odin to rent Gard to Marcone.
