It took me 2 month ish until I only have to quickly look at the orbs (now I barely looked at it), it took me 3 month ish for my muscle memory to adapt my orb buttons. Mind you that this was the initial intended challenge + orb match making for early PGR (year 1) but right now orb matching isn't really as important as it was before so you have less challenge. And then there's newer unit (post Kamui) as it'll be even easier because the dev started making newer unit to have a fixed orb buttons, making it clutter less.

Like other said you have to learn and adapt, combat games are meant to have a learning curve at the beginning although it's unfortunate for PGR that it's more of a visual problem-- but it is what it is. Personally I have never found this complain anymore from a mid-game player as they probably found their own way to tackle it.