we got shields before time slices. Remember the big issue was no shield cooldowns. So people could just endlessly buy 3hr shields back to back to leapfrog each other. No lead was safe to a bigger bank account
I remember that too; they quickly changed how shields worked afterward. There have been many times in the early days where players would exploit the mechanics of the game. First there was the heal to full health when adding 1 level to a character. Then OBW true team healing exploit by using easy Campaign nodes. Later the infamous 1 point node grindfest. Then we have the long list of broken character powers that were nerfed.
I would say the devs have gotten smarter over the years about considering potential exploits and curbing it before release.
if i recall properly, we need more events like Sakar Arena. where it was a small group of players and lasted an hour i think. It came out a long time ago and the devs gave up on it.