Linked MOBsFollow

I have aquestion about aggro on linked MOBs.

I was on an LMM (Lord Mithaniel Marr) raid last night. LMM has two wrulon guards which are (I think) linked to him aggro-wise. The raid used a monk to split them - however this was a VERY lengthy process and took MANY FDs before the guards could finally be pulled single and despatched leaving LMM alone.

I was wondering why you could not use 3 monks (or bards, or SKs, or...) and take aggro on one MOB each. Each could then be pulled to a separate corner and LD'd (faded, ...) leaving all 3 split immediately after one attempt. I think the answer has something to do with linked MOB aggro, but this is not an area I understand - can anyone enlighten me please?