What is the test for severance when there is an imbalance in the strength of the case against multiple accused?

Citing Guimond v. The Queen, 1979 CanLII 204 (SCC), [1979] 1 S.C.R. 960, this court acknowledged that a significant imbalance in the strength of the case against each of multiple accused was a factor in determining whether to grant severance, writing at para. 182: We do not suggest that the relative strength of the prosecution case against various accused is the only factor to consider where the conviction of one accused implies the conviction of a co-accused. It is, however, an extremely important consideration. The reason for that is apparent. Where the case against the accused seeking severance is weak and the case against the other accused substantially stronger, there is a greater risk that the jury will resort to the impermissible reasoning of guilt by association to shore up the case against the former.