I have been reading a bunch of threads on pull-pull systems and I am left confused.

1. Do the control arm and control horns have to be the same length? (I have read both equal and it does not matter)
2. Should you have some slack on the opposite side when control surface is being moved (I have read both; maybe this one is preferance?).

Now, everyone agrees if you do want slack, you need Ackerman. However,

3. Do you move control horn slightly fore or aft of hinge to get the correct Ackerman (I have read both options).

Lots of opinions (conflicting) so I am looking for the real answer. Thanks.