Do you have to "live with" non-sense logic or durations (in delays) just because it was approved in the baseline?

For example, in the last 90 days of a project the contractor had 45 days brick pavers, the FS 45 days landscaping.  What if both items will only take 20 days and can very easily be done at the same time?  Do you have to leave that 90 days because approved in the Baseline and you can touch it because you cannot direct "means and method" or can you call "bs" (that it is wrong) and have them reduce the remaining duration and fix the logic?