It's called random. If you focus on one or two chars, you can have over half of their armor with your best secondary, and 3-4 pieces with their best two within a month. You get four-five pieces per day in drops on average during your dailies (from named, glowing chests, and the occasional rare drop on basic mobs), plus enough apexis to buy at least one. The law of averages will give you a good piece (with your best secondary) every day, and an optimal one per week. Of course, as you progress, you get more optimal stats for slots you're already geared...
Remember: this phase is supposed to last 10+ months, so the random shouldn't get you fully geared after two weeks...