Franklancer. I am only level 9 Imp but generally I attack with mostly jumps. It is the only way to overcome hoards of guard reserve. Here are my tips based on my experience of attacking level 9 and 10 Rebel bases.
Generally I will avoid rebel bases if they have:
-both factory and barracks GR active (note however if they are out in the open I will still attack and will drop a single jump next to each to take out quickly before troops spawn. if they are in the hub of the bases covered by shields I will avoid).
-have very low resources to loot (unless I am just grinding for conflict gears)
-have both droideka active (I generally assume that if both droids are active then the base has likely not been attacked recently and therefore also likely the squad centre is full)
-I find it hardest when Rebels have SC with either buffed Jet Troops or Sullustan Snipers. Anything else in the SC is usually easy to deal with.
Also, from my own experience I spent ages trying to perfect my defense. I have got to the point where I might now win 3 out of 4 defenses (even against jets). You have to note the downside of this is you will loose far more loot than if you just lose the first defense. It may be preferable to lose in your first defense rather than win. Last week I was saving Contra for a droideka upgrade and won a number of defenses in a row but pretty much halved the amount of Contra I had in storage, then takes ages to loot it all back. Would have been much better to have lost the first attack. I have seen some Rebel bases where they put the HQ way out in the open undefended. I think this is the intention, a lure to ensure they lose the defense and get protection, rather than keep getting attacked.
Main account: Bacon (level 11)
Second account: nEggs (level 9)
Squad - NewSithEmpire
LINE ID: sgu97cab