The balancing with an immobile legend such as Crypto is simple: What advantages do you hope to gain?
First of, let's count up what advantages you gain. You can spy with a drone that is in no way linked to your own health. So it can both be considered a third, independent eye, but also a distraction. You can reveal enemies from far away, up to 200 meters I believe. So that's another advantage. Lastly, the ultimate cripples shields of enemies by 50, and slows them down. Although that's more for the ultimate.
The disadvantages are first of all his immobility. Basically, he's a sitting duck and for this duration he's vulnerable, the initial character is useless and likely stays behind if his team mates decide to rush forward. Furthermore, he doesn't gain any other advantages from being stationary. No cloak, no shield, no near-field sonar or anything. Enemies could practically sneak up on you and watch you play your drone and decide to 'accidentally' drop a grenade.
Vision and spotting isn't as useful as you think. Of course it's good to know where your enemies are. Equally as good however is even just the approximate location, because that prepares anyone enough to be careful.
Little do people know that Crypto's massive drawback is barely compensated. Having the ability to control a drone that does nothing but spotting and an occasional EMP is the equivalent of being a character with a single Arc star with massive radius until you decide to show up yourself.