think about it this way: victim and aggressor are fighting each other to see who affects who.
if the victim is driven by a small transistor, it means a switch in the aggressor net is relatively larger with respect to the victim. it will cause a high-magnitude glitch. On the other hand, if the victim is driven by a huge transistor, the aggressor will barely affect it. All of this is related to the effective C between the nets and how fast it can be charged/discharged.