Decide about the abolition but without saying anything. Call them alone one after another to Marineford for "reunion" (or something) where you have alredy ready all the countermesaures for the specific warlord. Start with weak ones to test the method all the way up to Mihawk, or maybe better to start with him and have 2 admirals welcome him before he can smell the smoke.
Also unlike giving in 100% to what Fuji asked make instead some specifications since the warlords are not all the same. Have bloodlusted warmongers like Doffy arrested like Fuji wanted (so Weevil, maybe Buggy) while leave guys we do wht they are asked and don't harm civilians (Boa, somewhat) and also that could be a significant threat to the navy as well (Mihawk). Pointing a stick to Mihawj when he was willing to help the WG if they let him alone could be a big mistake (anyway doubt Oda will go outside his way to develop this scenario).
Also unlike giving in 100% to what Fuji asked make instead some specifications since the warlords are not all the same. Have bloodlusted warmongers like Doffy arrested like Fuji wanted (so Weevil, maybe Buggy) while leave guys we do wht they are asked and don't harm civilians (Boa, somewhat) and also that could be a significant threat to the navy as well (Mihawk). Pointing a stick to Mihawj when he was willing to help the WG if they let him alone could be a big mistake (anyway doubt Oda will go outside his way to develop this scenario).