No voice can be a problem. For some, vocal Squad/Platoon leaders are in effect game guides adding to the immersion of the troops being herded. Without voice while some will stick with you on a 'I like being in this area' basis and some will stick because you seem to be going in their general (lane) direction, actually getting things done and moving from lane to lane (or worse, swapping conts) can be really hard to do as ppl arent sticking with you for voice guidance, immersion or wanting to be a shock troop platoon Rding everywhere like some of the effective platoons do.
To get to grips with any kind of platoon here you have to get the right people. There could be more subgroups but I find players fall into mainly 2 boxes at any given moment, fight seekers who will cap a base if its useful to them to do that and base cappers(/defenders) who will fight a bit for it but not too much. A single player even might swap between the two during one play session and as a platoon leader you need to set out what you want to do and let the ppl seeking the alternative come and go. Sadly voiceless squads dont tend to succeed as fight seekers.
Without someone barking at them to redeploy or kicking them out for not being in the right place then you dont really have a platoon at all, its just a random bunch of guys who find it convenient to be in that place together and there has to be some sign that you arent just a headless zergoon to the people who join through the minutes and hours you run it, voice does that.
FU are running pub platoons a lot lately, join them and see how they manage their squads. In a small way it can be a bit annoying if its a long wait for gate maintenance as i end up wasting a lot of implant energy but it certainly keeps the squad alive, fresh and with people who know what the delete key does (and when to use it).