I ban you for having bad rhythm.

I light up the caves in all of my PS fields, especially where I disable the "prevent-mob-spawn" flag.  For example, if you have 4 PS fields intersecting at the center of your monument, and they have that flag disabled, Guardians will spawn but mobs will spawn in the caves beneath the monument as well.  Then as the Guardians die, the caves may get more mobs causing less Guardians to spawn.

Lighting up those caves guarantees only the Guardians will spawn.  If you light up ones leading out of the PS fields, there will be less chance of mobs wandering in to the Guardian spawn area to reduce the Guardian spawn rate.  As a bonus, you may find gold and diamonds in them there caves 

Guardian +1, Blaze -1

Blaze - 9
Cow - 12
Creeper - 10
Donkey - 11
Ghast - 14
Guardian - 13
Llama - 13
Mule - 10
Pig - 12
Pigman - 11
Skeleton - 8
Sheep - 10
Slime - 10
Witch - 7
Zombie - 10

Eliminated:
Chicken

Sounds like a good plan   

My first major project on Famcraft was to create my "Guardian Slayer" which I still use.  It only uses about 40% of the spawnable area for Guardians but most of the original monument is still intact.  It starts with one layer of source blocks up top which flow downward for many blocks into open fence gates.  They then drop into flowing water which feeds them to one of two 2x2 drop shafts.  After a free fall to like Y=10 they pass through a lava blade and hit 4 hoppers.  If the fall doesn't kill them they bounce back up into the lava until they die.  The hoppers then collect the items to a chest.

If you didn't care about preserving the monument like me, this would be a fairly efficient design.  So assuming you use the full spawning area:
Pros:  Fully automated, decent drop rates, and fish drops are cooked 99% of the time.
Cons:  Fall damage doesn't kill Guardians which may slow down spawn rates.

I ban you for having more forum posts than I do.

All of the available monuments have been sold!  Thank you everyone who bought one.