I can see where you're coming from. There are arguments against that, however. If you're getting snuck up on from the brush, it's your roamer's fault for not providing vision. If that happens, then a reflex block and boots should suffice to get you out. Building burst, fights shouldn't last long enough to get you hurt (if you're not the one initiating).
However, being bulky does synergize well with the Broken Myth. Plus, Shatterglass is very expensive. So it all depends on the timing. If your team has the momentum through the midgame, you can rush offense to get the game over with quickly. In the evenly-matched late game, however, item leads are not as important as simply surviving, get defense. The segue from mid- to lategame is often where you'll choose for either the fourth tier-3 item or defense.
Edit: also, if you're desperate, you can spend all your money on infusions for a quick upper-hand.

Yes, Alternating Current + Broken Myth is a very common Vox build. Also high five Smash bro!