Sounds like a good plan and it might work, as long as Oldry doesn't just build a bigger fleet as soon as he sees you 
My objective is to have 1.5x his fleet size to attack him.
Plus, he's building attack fleets. He sent 20 cruisers a few turns ago to attack one of my planets; he just launched 40 frigates from Pi Circax, my target. It seems to me his strategy is to repeatedly attack my outlying planets in the hope of distracting me from producing a large attack fleet. I'm gambling that I can shift resources around enough that I can hit him with a huge attack fleet before he is able to beat my main attack.
The real risk is if he constructs planetary defence, then you may as well give up.
I've considered that. However, I think he actually might not do it. His planet has fairly low population, thus low GDP. He's already got a major disadvantage in terms of productive output on that front, I think he may not want to sacrifice the resources needed to build fleets. If he gets PD, it's easier for me to overwhelm him with numbers of ships. Plus, now that my fleets are withdrawing, he may be wondering if I'm going to attack his other planet.
SPeaking of: do we know the garrison on his other planet?
