Dunno. Interesting question. Looks like you already know a lot more about it than I do. From what I've read, the Germans overbuilt later models of tank in a pointless attempt to match the Soviets, and the most reliable model (perhaps uncharacteristically) was the one they built the most of. Sooo, wild, uneducated guess, is that this division you mentioned eschewed the newer, larger models.
I just finished (read over a period of months, on the weekends) the old memoirs of Omar Bradley, "A Soldier's Story" (1951) and it's thick, goes into minute detail about a lot of things, and has an excellent index. Naturally he discusses St Lo, and the Falaise Gap, but I can't recall what German units he singles out (if any).
Hope this helps, and good luck with your novel.
Thanks. You're right about Lehr, as well as other divisions. The most reliable tank the Germans ever built was the Mark IV. However, it didn't have sloped armor, and got chewed up by the T-34, as well as the 85mm variant that the Russians introduced in 1943. Tiger I was a desperation move that began in the Summer of 1941 after the battle of Smolensk. T-34 made its appearance, and made short work of the Mark III's and the Mark IV's. The T-34 was only stopped by judiicious use of the 88 mm FLAK gun as an antitank weapon. The Mark V Panther was a well thought out model that is considered by most experts to be the finest tank of that war.
Be Seeing You,
Chris