Another problem with keeping Watts as a part timer in this role is if you look at all the premiers this century, the filth in 2010 are the only team that had one specialist ruck with a part time pinch hitter in Leigh Brown. All the others have played two rucks, with one playing mainly as a forward.
As many have pointed out, Weideman is still very raw. Best case scenario and Hogan stays, there's no problem with making the Weed earn his spot at Casey and having him come in when injury/suspension/form warrants it.
Tom Campbell from Western Bulldogs & even Shaun McKernan at Essendon are two role players that I think are worth looking at who could fill this void. Certainly not stars, but fit the club bill of competative and physical players. Both mentioned in the attached article and both have reasonable numbers.
http://www.afl.com.au/news/2016-09-14/delisted-whos-on-the-chopping-block-at-your-club
TOM CAMPBELL
http://www.westernbulldogs.com.au/player-profile/tom-campbell
http://www.aflplayerratings.com.au/Ratings/Player/114689/Tom-CAMPBELL
SHAUN McKERNAN
http://www.essendonfc.com.au/player-profile/shaun-mckernan
http://www.aflplayerratings.com.au/Ratings/Player/112847/Shaun-MCKERNAN
Campbell turns 25 this off season and McKernan has just turned 26, so both have plenty left in the tank. On top of this I'd like to see the club draft Darcy Cameron from Claremont out of the WAFL, who's another option for this role going forward. Has played mainly forward this year to good effect while previously mainly being a pure ruckman. Only turned 21 this year, so has had some miles in his legs already, so if required should be ready for senior football. 36 goals in 2016 while averaging more then 12 hit outs a match.
http://www.wafl.com.au/players/view/4672
Just my thoughts anyway.