There were only three ILbs of the size and experience needed to play the position in the Pats 3-4 version. There are almost a dozen OLB candidates.
In the order I liked them Laurnaitis by a country mile, followed by Sintim and Mauluga bringing up the rear. Rey has subsequently fallen with his poor Wonderlic. The position in addition requires a pretty smart and perceptive play caller as the "mike". An unrecognized need is to diagnose and call adjustments prior to the snap. I doubt that Mauluga is up to it. I think he is a two-down ILB and only better than Jasper Brinkely, who can be had, 3rd round on. The runstuffer ILB is going the way of the dodo like the FB position. TJ theultimate runstuffer was only a parttime player with BB from 2003 onward. He preferred Phife instead, an all around ILB, but not as good as Lauranitis who his game resembles.
People criticize Lauranitis for not shedding superbly only fairly well, and making the tackle. Baloney. He had 363 tackles in his career, he must be doing something right. He can pass cover and make INTs. He holds more, 9 INTs a fantastic number, for a DB, never mind a LB. That is more than first round "playmaker" DB Vontae Davis (7) had in his career, and more than double what Mauluga got (4).
He can ILB blitz. Mauluga did little of that and Sintim's experience is OLB blitzing which is completely a different technique. Outside, one needs to get bye a tackle and bend-in in a foot race. I think Sintim could adapt after a while, but no guessing how good he could become at it.
The ILB technique is usually a delayed blitz, avoiding or sliding by everyone in a direct shot to close the pocket and charge right in. More like a penetrating defensive tackle does, like a John Randle or need a I say the all time NCAA sacker from DT, not DE, Tedy Bruschi. Occasionally it is a direct penetration into a hole created by a pulling lineman. With the unexpectedness contributing as the blitz-pickup RB is tied up with helping an outside defender, or is on the wrong side and out of position. Neither Sintim nor Mauluga exceed Laurnaitis ILB blitz sacks or tackles for loss, that come from pre-snap diagnosis, and smart instincts.
Take the rarer ILB first and the more plentiful OLB, second, 23, 34.