run block basically says what it does: gives a slight bonus to blocking on running plays. on an inside run, I'd much rather just use brute strength at the C than high blocking. a C should be able to hold their block easily with 80+ blocking already.
now, if you said 10 get low, maybe you'd have a point
38 SP to get line gen to 9. Try an AE piece that you get to +4 at level 40. Then you only need to take it to 4 base (+4+1 equip), so you'd need 1-1-1-2-4 = 1+1+1+2+(2+2+3+3) = 15 SP.
Wow, a line gen piece saves 38-15=23SP? You know it! Start shopping, and spend those 23 SP on.. 60 agility