Now that, is a complicated question.
For the OL your direct competition is the guy you are lined up against. For OT's that is typically DEs, for a OG it could be a NT,DT or even a DE. For C's its a DT/NT or in some cases no one

There are only a few things that happen during a block
Run Block:
- Pancake the D
- Get your block broken
- Hold block
Pass Block:
- Shock Block
- Get Stunned
- Make Block
In most of these, the more strength you have the quicker you can pancake or shock block the D quicker than they can break your block or stun you. That's my feeling on it. You need to put them down before they put you down. You can try to out agility them, but for everyone save the OGs, DE and DTs all receive better level bonuses for AGI.
So, my feelings are bring the strength and work that way. Not saying it's the only way that works. I have not found that there exists "too much str", only not enough "supporting attributes". You have to decide how your dot plays best.