Alastor was making lists in his head as they spoke - who to speak to, who got what assignments, how the information would need to be put together... But, he was still paying complete attention to what Dumbledore was saying about splitting the work, getting Vaisey involved. "Likely best if we set aside a room for this. I'd say we could use McKinnon's, since she seems to only need the wardrobe space. But, it'd be more secure to keep them in the main house."
Pausing as Dumbledore continued, Alastor's eyes narrowed curiously. He wasn't unaware of the chaos the Order had been left in after his time -- for he'd finally gotten around to reading his own history and he'd died not long after Dumbledore himself. Sound planning would be needed to draw such disparate factions together in the unfortunate event the loss of their leader should befall them again.
"Well," he said slowly, "if knowledge and focus were all we needed, I'd say Snape. I know you've passed things on to both he and Potter that haven't made it to anyone else. And Potter doesn't have the focus. Good man. Decent Auror. But, when it comes to the tough calls, I don't know that he could always make them. Snape could.
"But, if you're inviting honesty, Sir? Snape's personality is as likely to fracture the team as my own would. While I can see certain factions more likely to follow him than they are even you, others...?" Alastor shook his head. "He'd be fighting for control as well as fighting a war. Still, of anyone we have now, he's your best bet if you're looking for a Second in Command who could take over if it became necessary."