Immediate Staple for Chapter 2 Rogues. This is arguably the best 0XP rogue ally even in Chapter 1, providing a bonus stat and an extra action (So long as that action is to move) for a reasonable amount of resources. In the context of "a core set that doesn't cause issues down the line" color me disappointed on this one. I would've preferred to see a card closer in power level to Cat Burglar (1).
With respect to the full cardpool: There are going to be decks that prefer other effects (like gaining resources with Bianca "Die Katz" or getting an extra action to play items like Joey "The Rat" Vigil or boosting with Robert Castaigne. But Olivier has the same advantages of the venerable Dr. Milan Christopher of being a general-purpose slot filler that improves exactly what his faction wants to improve - which is going to make him a consideration for nearly every rogue deck, even if Olivier doesn't ultimately make the cut.