Yeah your the dice gods decided not to like you this game, but I think you were missing 1 factor when playing Clanners.... Their Pulse Weapons.
For example the Vulture C is a great duelling platform, but you want the Prime for that -2 to hit at the extra 3 hexes you get on the IS weapons on the S/M range border, or better yet the 7 hexes you get on the M/L range border, let alone the extra damage. The range game played with the ER weaponry in the 8/15/25 vs 7/14/19 is fine (sweet spot 15 hexes), but a lot harder to play in my experience than teaching your opponent to fear your pulse weapons.
The 6/14/20 of a clan large pulse vs. the 3/7/10 of the IS equivalent shows why there are hardly any IS designs with LPLs. Though the medium pulse isn't quite as fearful as the LPL, it strikes the balance between weight/damage and gives an amazing -2 targeting bonus. The medium laser is really the workhorse of the game and there's a reason the Blackhawk S is loathed.
Put another way, the pulse negates a movement modifier of 5 hexes, or eliminates the long range bracket... it should and does strike fear into lights (like that Stravag Hermes) everywhere.
Yes your Puma can and does strike fear with it's 2 ERPPC's but I'd more fear something that can fire a little bit more often, like the LPL variant (B)... Yes it doesn't do quite as much damage, or cause enemies to quake in their boots, but it hits more often, and that's why the guys with the higher hit percentage are more valuable than Casey Jones any day.