Agreed. Clantech or not, facing odds of more than 2 to 1 is almost certain death just because of the die rolls. The first, best, and only way to win that fight is to force them to spread their forces and defeat them piecemeal. A star vs. company of upgraded IS tech, including some salvaged Clantech, will be a defeat for you. A lance vs. star engagement is a victory. So you have to take advantage of your range and maneuverability to keep only one lance at a time in effective combat range. The lesson about mutual reinforcement is your golden ticket.
Just to give you a pointer, consider a battle I once gamed out with about 30 other people once. In this case, it was a battalion vs. trinary fight. The trinary's objective was to advance across the board, where our objective was to stop them. We had hidden positions and prepared positions. Unfortunately, we also spread our forces too thin, so when they ran over our right flank, I (out on the left flank) could not support without leaving my hidden positions. Quite literally: I had a Kintaro with a maximum range of 15 hexes. The other end of the line was about 19 hexes away, and they were shooting from a range of 5-6 hexes beyond that. I was only able to contribute a) because one star ran at me in an attempt to envelop the company on the right flank, so I could get to medium range in a single turn of movement, and b) we didn't have a choice in moving out, since the company on the right would have been obliterated if they had faced the combined firepower of an entire trinary for another turn. Map it out, and you'll have a good conception of how valuable turning a flank can be.