Possible minion/mount system for Fate

The Fate game I'm running now isn't using the Drive/Ride skill, as I've often found it to be too situational, and one of the characters has something of a familiar, so I've been trying to think how to handle minions and mounts within conflicts. I read some good posts on treating them like aspects, but that feels like a significant investment for a horse or the like. It might work out well for followers or mentors, but we're in a weird gray area at the moment.

So what I plan to playtest tomorrow is:

• Mounts and minions are Extras.
• Mounts are free from a character-building perspective, though might take in-game resources to acquire. They have statistics akin to Nameless NPCs.
• Minions require a refresh point and have stats akin to a Supporting NPC.
• You choose an appropriate skill to control the minion or mount with. You could control an average mount with Provoke, Rapport, or Empathy. A minion might be controlled by those in addition to Deceive or Resources. In my game there are some magic skills - the minion in this case will be controlled by one of those as it's an imp formed of its owner's blood.
• You can use their trained skills in place of your own within a conflict, but you use the lowest of that skill and skill you're controlling them with. So if you had Athletics +0 and were using your Empathy +2 to control your mount, which has Athletics +3, you can make an Athletics check at +2. If your Empathy was +4 you could make an Athletics check at +3.
• Normally there is no need to roll your control skill, but I can imagine situations where opposition or the environment will attempt to break your control and you'll need to roll defensively to maintain it. I'm thinking that would be an Overcome action on their part and if you lost control it would be another Overcome action to regain it.
• You can spend a Fate point to allow the mount or minion to act independently for a round in a conflict. You decide its actions.
• You can spend a Fate point to use the higher of the control skill or the minion's or mount's skill.
• Their aspects can be invoked and compelled as if they were your own.
• They could have other effects on the narrative. If you are riding a horse it's fair to say you can travel faster and carry more, or pull a cart, without going into details.

Anyway, we'll see how it goes.