Yeah, basically I dread attacking any planets that the New Republic owns with my Imperial Army. While usually I can win the space battles over the planets with few to no casualties at all (maybe a lancer or two max usually) due to the good old SSD rush followed by star destroyers and lancers.
As for actually taking the ground of the planet though, this is a hugely different story. Sometimes I get lucky and they don't have time to build up the planet into a huge super fortress, and only have some minor casualties, but the usual case is the New Republic uses every build slot available for heavy vehicle factories, turbolaser towers, and of course, infiltrator academies.
My army consists of about 15-25 units of stormtroopers usually, 5-10 TIE Maulers, As many AT-ATs as I can stuff into the army, plenty of IDTs and Scout Troopers for scouting the map for bombing runs and what not, and pretty much the entire Imperial roster in one giant army. (around 60-70 units usually) and everytime I invade one of those death traps I lose at least half of my entire force. It makes it hard to rapidly expand against the NR while the Pentastar Alignment seems to have no issue doing the same in a different part of the galaxy.
What am I doing wrong? My armies tend to do better against other Imperial forces, but those T-B tanks tear through my troops (and sometimes nab an AT-AT or two as well), while the infiltrator spam is usually just a nuisance, once in a while those Thermal Detonators get past my detection and blow up half my army. I've currently resorted to spamming stormtroopers, scout troopers, and IDTs as scouts to find there base and power generators and just bomb them, wait for the timer to reset, and do it over and over again. Then I rush in with AT-ATs and TIE Maulers with Stormtrooper support, and hope for the best.
Any ideas guys? (Oh and another thing, what's an easy way to kill a certain Pentastar Alignment Star Destroyer controlled by a certain Grand Moff with only light and a few medium ships? He's been conquering plenty of my outlying hold out systems with just himself, Octavian Grant, and a Praetor, sometimes more. I killed the Praetor and Grant in a battle over Ciutric which I lost, but by little, so now he travels by himself in his Star Destroyer. I sent my main battle fleet with Isard after him now, but he tends to be really sneaky, so I need to set up a good trap, any advice?