Double check this for me please.

[Blackwater]

OK, I have just started dualboxing 2 locks (I have done other toons before) and I am trying something different. I want to clean up some of my old school macros and try using the newer ones (focus, assist without focus) and so on.
Jackalynn (Main) and Gracemarie (slave)

For my slave lock

The old way would be something like this:
Button 1
/target Jackalynn
/follow
/assist

Button 2
#show shadow bolt
/assist
/cast Shadow bolt
/petattack

Newer way:
Button 1
/focus jackalynn
/follow focus
/assist focus

Button 2
#show shadow bolt
/assist focus
/cast Shadow bolt
/petattack


Now I looked on the wiki for assist without focus here and noticed this : (substituting Jacklynn for Daria)

/cast [target=Jackalynn-target,exists,harm,nodead] Shadow Bolt

Which way is better? I have been noticing that:
1) If I switch targets on my main sometimes it doesn't switch them on my slave, I have to repress 1 to get the slave to switch.
2) if the target dies, and somehow I re-target something, my imps are blasting that. (BAD IMPS).

I thought using Focus would say, what ever Master is targeting, slave will also target?

[Ualaa]

I like the second approach better.

Neither is faster then the other, as far as acquiring a new target.
But you don't need to press a button to target the main toon, and then another to dps.

The focus approach is a bit better in one regard.
Both toons can /cast [target=FocusTarget], so the leader is interchangeable.

[Blackwater]

Reading more from the wowwiki...

http://www.wowwiki.com/Focus_target