How good would PD have to be for you to make gobs?

[Huzurdaddi]

So after reading the PD post I started thinking how good would PD have to be for me to consider buying it instead of castles for defence?

So I came up with the following examples of INSANE PD. Yet when I talk to people the would still buy castles.

For example:

-- Pythium
-- basic leader: Emerald Lord
-- basic troop: Principes ( 2.0 )
-- advanced leader: Arch Angel
-- advanced troop: Angels of the host ( 1.0 )
#selectnation 2
#defcom1 6
#defunit1 10
#defmult1 20
#defcom2 465
#defunit2 543
#defmult2 10
#end

-- Man
-- basic leader: Mother of Avalon
-- basic troop: Tower Guard ( 2.5 )
-- advanced leader: Firbolg
-- advanced troop: Kithaironic Lions ( 1.5 )
#selectnation 3
#defcom1 152
#defunit1 63
#defmult1 25
#defcom2 559
#defunit2 514
#defmult2 15
#end

-- Ulm
-- basic leader: Black Lord
-- basic troop: Crossbowmen ( 2.0 )
-- advanced leader: Troll King
-- advanced troop: Living Statue ( 1.5 )
#selectnation 4
#defcom1 70
#defunit1 417
#defmult1 20
#defcom2 519
#defunit2 474
#defmult2 15
#end

So I just want to know if the PD were at such insane levels would you buy 20+ of it instead of castle ( 25 PD ~= to 1 watchtower in cost or 30 PD for a castle ).

I'm not really asking if people think this is a good idea for the game it would clearly change it a lot. I'm just asking if you would build this "crazy" PD or castles/watchtowers.