It depends on the situation, True Purple.
Having 2 stacks of enchanted weaponed shirers and slingers behind an enchanted Air sphere wall is much more effective than an additional stack of fire sprites. The point is - if there are easy ways to exploit the system, experienced players will do so. And new players will have a severe disadvantage - which is what will happen if upkeep is low enough.
Now, however, anyone who has a reasonable understanding of how structures in Dwiggs helps can have a long-term strategy of heavily enchanted units - you just need to plan the additional infrastructure. Today, in a game, Merk had a whole stack enchanted with Bless, Stone Skin and some with Free Movement or Enchant Weapon. I myself had 3 stacks with Stone Skin and Bless. I am not trying to be arrogant here, just pointing out that if you build the infrastructure, you can do it (and I had only 4 towns).
Even now, by turn 50 or so (in multple games), I have seen Air cast mastery, haste domain, watcher and have 2 karagh stacks enchanted with wind walking (sometimes, the units and enchants vary, but I think you get the picture). So, if you understand how its done, its doable - which is why I always say, you have to adapt to the game, shouldn't expect the game to adapt to how you play.
Btw, if you check the properties of the DM1.4.xls, you will find who Dwiggs really is! 
Nice to see you still keep an eye on things here, Dwiggs!
2009 1v1-Mapmaking Champion,
Former PBEM Singles Champion,
Proud contributor to the UPatch 1.4 and 1.5 effortWar of the Twins- 1 vs 1 PBEM map,
Too Much Water - 1 vs 1 PBEM map, winner of 2009 1vs1 Mapmaking Challenge
My Dragon Age development
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