If the block is off enough I would be tempted to redo it. When I am making a block like this, I will square up each of the sub units - before cutting/trimming them, I check the points and any other places where they intersect with other units. Easier to correct these issues when you do not have to rip out a huge amount.
Another option (depending on the setting that you are using) you might be able to add a small frame of the background around each block and square up to a larger block - thus enlarging the block slightly and saving the points.