Looking for opinions on rear channels

Are jbl L830s unsuitable as rear channel speakers when used with jbl L890s as front channels powered with an onkyo rz840 in a 20’ x15’ room?

I used to have some older bose bookshelf speakers as rears and was very happy.
Worried that the rear channel outputs on the Onkyo RZ840 wont support the large L830 bookshelves as rears.