Tongue was just an average bench utility from 2000-2002, he barely played at all over 2003-2004, and 2005 was again just an average bench utility. He did admittedly have an outstanding season in 2006, one of the best seasons by a lock I have seen in a long time, but since then, what?
2006 - 25 games, 11 tries, 10 linebreaks, 2 LB assists, 1 try assist, 18 offloads, 47 tackle breaks, average 9 runs for 66 metres, average 44 tackles
2007 - 22 games, 2 tries, 3 linebreaks, 5 LB assists, 3 try assists, 9 offloads, 27 tackle breaks, average 8 runs for 48 metres, average 35 tackles
2008 - 23 games, 2 tries, 6 linebreaks, 7 LB assists, 9 try assists, 12 offloads, 26 tackle breaks, average 5 runs for 36 metres, average 30 tackles
2009 - 22 games, 3 tries, 4 linebreaks, 5 LB assists, 5 try assists, 14 offloads, 21 tackle breaks, average 6 runs for 40 metres, average 32 tackles
Admittedly, last season and this season he has played hooker which has limited his game, but really, apart from a top season in 2006, what has he done? Running metres below 50, tackle breaks barely more than 1 a game, pretty low offload rate, his tackling workrate has gone down a fair bit since 2006 too. The only real thing he has kept going for him is his try assisting skill, but still.
Raiders have a better halves combo in Campese and Herbert/McCrone, a better hooker in Buttriss, and a better lock in Fensom. Tongue really isn't needed. He is 30 now too.