it all depends.
if your game is organized nicely you can reduce number of events for your whole game.
for example - if you create a family that has 10 enemies - you need only one trigger where you say - if myfamily.health <0 do ... something (explode, count score etc..)
other way could be : if enemy1.health <0 do... something ( explode, count etc..)
if enemy2.health <0 do... something (explode, count etc...)
.... and so on for each enemy. this means - > 10 events for each enemy instead of 1 where you just drop your sprites to family.
and such "optimizations" could be done to reduce number of events. you can achieve that wih families and functions easily. and creating new levels, spawning and all other things are suddenly super easy