Maro can play anywhere pretty well, but for me, I want probably one of the top 4 SRs at SR providing the power and have three backrowers who do the job day in, day out.
And that was emphasised for me in our win vs Sarries when regardless of Billy and Maro (and George and other big names) being part of their pack, it was our mobility that caught them out. And however good you are as a SR playing as a 6 (I know Maro wasn't vs us...) you aren't as good as Curry x 2 or Earl or Willis x 2 or any number of others.
It made little difference if Lawes was 6 as it was only at scrum time that the number made any difference. Maro plays "like a flanker" having pushed or jumped, it's just that the policy leaves you one flanker down. And as for the game vs Georgia, with Billy in slo mo, and Maro as extra SR, Jack was virtually having to operate as a sole back rower.