As mentioned above, Aribo is a player who thrives in space and opposition tactics (i.e parking the bus) will negate a key part of his game if played well. I believe though that it's more a case of our formation not suiting his natural game as opposed to him being played out of position.
At Charlton, Aribo played 9 times out of 10 on the left of a midfield diamond behind a front two. As such, he was largely allowed to dictate what went on in the left forward areas. A heatmap on Gernet shows this. Usually, he was the furthest forward player on the left in their team and as they played much narrower than Rangers, he often cut in and attacked centrally. If anything, he played wide left more than head of the diamond or no.10 and was the key attacking player in that left area.
With Nigeria, he's actually been deployed in a much further back, central role. That said, he appears to have taken it upon himself in his Nigeria games to play as a box to box midfielder, outshining Iwobi at No.10, so much so that Nigerian fans want him to play in a more advanced, central role, behind the striker. Again though, Nigeria play a much narrower game than Rangers.
With us, it's all about the width...save Jack of late, our midfield plan seems to be....get it wide at every opportunity. Rangers play with two advanced wide men and two very attacking fullbacks so the flanks are often overloaded. Aribo never experienced this at Charlton nor with Nigeria as neither play(ed) with real width with the midfield being largely instructed to get it wide. So you get Aribo on the left with Kent advanced and often also Barasic so he drops off. He can't charge into the box as he would no doubt like as he's often left defending the entire left flank - see Hamilton's breakaways for example with Barasic, Kent caught upfield.
Gerrard seems settled on his formation so where Aribo fits in is a bit of a mystery. He was tried wide left vs Celtic to drastic effect (hideous formation all-round that day to be fair) and that's Kent's position now. Jack is firmly the box to box midfielder of the team now and both Davis then Kamara seem more favoured in the anchor role. Kamara it seems is also better playing left of Jack with Davis behind in a midfield three. It would appear Aribo might be best suited just behind the striker but we're rarely going to play that way, preferring width with one up top.
Aribo is a talent no doubt but we're not going to see the best of him unless we change formation, lose Kamara and he ups his standard, mix up our game more (signs of Gerrard trying this) or play against an open, attacking opposition where he will shine.
P.S He also got his head ripped open, needing 20 stitches by a typical "Welcome to Scottish Football", no yellow card numbskull and he's our player, not a loan so let's give the young guy a chance!