I'm surprised about the Conways. I have a seen a lot of 1970-ish work that was done to substantiate N1 as a primary thrust parameter for FAR 25 cert.
As for ancient design philosophies, I was thinking more about the high compressor design. One manufacturer always attempts the same OPR with fewer stages. Then again, that same manufacturer has more success at high turbines than another brand. Each brand has their typical set of problems. That makes the newer "joint" brand engines quite interesting - each company can work to their strengths, though the bar has hopefully been raised from the V2500.