The stats of his tenure at Souths says it all.
In 2015 under Maguire, even with quality cattle, their attack was 8th best, with negative PD.
In 2016 under Maguire their attack was the 11th best. The team included Inglis, Nathan Brown, four Burgi, Angus Creighton, Luke Keary, Adam Reynolds and Cody Walker.
In 2017 under Maguire their attack was again 11th - and with a team including Inglis, three Burgi, Damien Cook, Creighton, Doueihi, Gagai, Campbell Graham, Reynolds, Sutton and Cody!
In 2018 under Siebold, their attack was easily the best in the comp. And with a similar team.
That should make clear where the problem lies. We could do worse than saying goodbye to Madge and bringing in Flanno and son IMO.