The drawback is that the whole point of it is to make things so bad in the realm that you have to go to war. The purpose of it is to let the majority of the players in the game who don't get to play the "Council Channel" aspect have something to do, and to force the Councils to find a war for them somehow.
Advies culling all the spawn is an unforeseen consequence, so perhaps increasing monsters/undead as a an affect of TMP would help things out.
When I suggested this alternative TMP system, I did not have this in mind, nor such drastically fast changes. I had in mind a system which's penalty speeds were slow enough so that if you spent all of your time training, your unit's training score would still overall increase. And it wasn't to make that realm's leaders so desperate that they'd jump on any random gangbang just to stave off the penalties, but rather to make them a weaker and weaker realm over the course of months, so that *other realms* get a greater incentive to attack them.
It was all about giving an edge to militaristic realms over pacifist ones, not about paralyzing pacifist realms. I've always firmly believe that even if we might want to encourage certain behaviours, this is still a game where people collectively decide what to do and how to do it, and that there is therefore no point in preventing people from doing what it is they have chosen to do, other than frustrating them and causing them to act in ways that make no RP sense and cause lame and hollow conflicts.
