Switch Veteran's Scars and Insight?

Since my idea about 2v0 minion gold was so well received (in hindsight, it was thematically displeasing), here's another one. There's very little incentive to take Perseverance over Insight or Veteran's Scar's over Runic Armor. One outclasses the other in almost every way. Sustain does just as much as health does provided it isn't interrupted (very unlikely early game). RA outscales VS late, so we take RA. Why risk the 1v1 or 1v2 (i.e you aren't Mundo) when you can just use your (far more versatile) summoner spells more frequently?

So why not let VS give a set amount of health and let Insight take its place as a 5 point mastery?