How much stress?

By Memorare, in X-Wing Rules Questions

Ghost/phantom with Tlt and Tactician fires at an enemy ship at range two within arc - once with primary and twice with tlt at the end of the combat phase.

Am I giving that ship three stress or two?

Two. TLT only gives out a single stress for both attacks.

Ta!

Follow the timing chart on page 8 of the FAQ.

Tactician resolves during step 8, which only happens after you complete the "perform this attack twice" loop.