I'm currently working on my 2nd and 3rd legendary tamers. I know glutton for punishment. My question is it legal to pre-tame animals of the appropriate level with my other tamer and then trap those animals in a room so they don't wander off before my other 2 tamers have a chance to tame them. I get great gains this way.
That part needs further definition.
To the extent of does this trapping prevent any aggressive MoB from being able to be aggressive vs the tamer.
If so, then yes that is illegal.
When My stables are full (kind of the same scenario as yours if you think about it), I will release my NEW Pet in a safe (for me) spot. I do have stables in one of my house. Go to the stable and get the pet I am going to NOT stable, put the OLD pet in a safe (for me) spot. Go retame the NEW pet and stable it. I MAY choose to leave the Old Pet were it is OR I may go release it at one of the Fel Gates.
If it is a pet that can perform range attacks, then the test of Have I prevented it from being aggressive is NOT passed as it can clearly attack me. I have in fact died from a Greater Dragon in a Stable, in the House.
If the pet can NOT perform range attacks, then yes your violating the rule and it is illegal, should anyone ever see you and choose to report you.
In almost any case for me it is simply NOT relevant. I am a Peace Tamer. I just peace the MoB and retame it. So a Frenzied Ostard for example, I peace it, it gets tamed. That Frenzied does not need to be pen'd up. A Greater Dragon, it can and does cast spells on me and perform the Breath Attack. In short it is attacking me and doing damage, it can be pen'd up. I peace it (it is hardly a 160 to barding difficulty once tamed). Once peaced it is hardly an issue of the Rule as It and I are simply encountering each other according to our skills.