Annexation was a strategy used by Columbus OH some years ago to continue growth past the limits of its suburban sprawl (and officially past the size of Cleveland, making it defacto the largest city in Ohio). Cleveland has been talking about doing the same for some time now, but I don't think the state government has been very supportive. Cleveland proper isn't large in itself, but the metro area is about the size of Austin: https://en.wikipedia.org/wiki/List_of_Metropolitan_Statistic...
A negotiation for merger between Cleveland and East Cleveland was shot down last year because of some pretty ridiculous demands by the EC leadership:
http://www.cleveland.com/metro/index.ssf/2016/08/east_clevel...
Some discussion at the time: https://www.reddit.com/r/Cleveland/comments/4zeubq/east_clev...