Equally, in Robins' mind he probably wasn't forecasting for the loss of both Godden and Walker long term.
In theory Baka, nor Biamou were meant to play much of a part this season so dedicating time and resources to bring in a 3rd choice striker was futile, as it would quite clearly be a hard sell bringing in an adequate striker who's happy to play third fiddle.
Realistically it's far easier just to take the calculated risk of extending Baka's contract for another year to ensure that there's at least some cover behind Godden and Walker, and just hope it wouldn't get to the stage where he'd have to be called upon on a consistent basis.