Not a good mix, you should really run 2 matching cabs. 2X 16 ohm cabs = 8 ohm load, 2X 8 ohm cabs = 4 ohm load.
A full stack it a club is pretty much overkill (although overkill can be fun at times), if it is for show, just stack them and use the bottom cabinet, the soundman will thank you. Also, on a small stage, a top cabinet pointed at head level can be more of an annoyance than anything. Even EVH, George Lynch, and most of those guys back in the day of the "walls of Marshalls" were usually only using the bottom cabs, and usually not all of the bottom cabs.
If you must do it, most important, don't set the Marshall at 4 ohms. Next, 1X 8 ohm cab + 1X 16 ohm cab will be a 5.3 ohm load, so set your amp for 4 ohms (or if it is SS, make sure it can handle a 4 ohm load). Also, it won't split the signal equally, the 8 ohm cabinet will get 2X as much power as the 16 ohm cab.
