I see some people saying ''why Doflamingo wasn't summoned as Holy Knight'', to do what exactly? Being a minion of Garling is better than being King of Dressrosa?
They already told Doflamingo he can't return to Marijoa thats one reason, Dof was strong enough to survive Government's attacks:
''I am a fugitive holding the most dangerous card of all. When they realised they couldn't kill me no matter how hard they tried... Celestials become awfully cooperative.''
Why would he become an underling of Garling when he holds the most dangerous card so he can blackmail them?
Doflamingo was blackmailing them, and controlling them, and basically had controlling both blackmarket and Government, also was king of Dressrosa, thats better than being underling of Shamrock or Garling, even if they want him as an underling Holy Knight, he would be more useful as Warlord, he was selling them weapons:
For that reason, Doflamingo was the most dangerous Warlord, more dangerous than Mihawk:
Of course they would want him as Warlord due to selling weapons to Government, after that Government had to make business with Kaido which was trouble for them, Dof as underling of Garling would make a small difference, more important as Warlord.
They already told Doflamingo he can't return to Marijoa thats one reason, Dof was strong enough to survive Government's attacks:
''I am a fugitive holding the most dangerous card of all. When they realised they couldn't kill me no matter how hard they tried... Celestials become awfully cooperative.''
Why would he become an underling of Garling when he holds the most dangerous card so he can blackmail them?
Doflamingo was blackmailing them, and controlling them, and basically had controlling both blackmarket and Government, also was king of Dressrosa, thats better than being underling of Shamrock or Garling, even if they want him as an underling Holy Knight, he would be more useful as Warlord, he was selling them weapons:

For that reason, Doflamingo was the most dangerous Warlord, more dangerous than Mihawk:

Of course they would want him as Warlord due to selling weapons to Government, after that Government had to make business with Kaido which was trouble for them, Dof as underling of Garling would make a small difference, more important as Warlord.
@MonsterKaido @Sir Yasheen @BillSlipton @Embers Kaios @Blackbeard @Yo Tan Wa @Wh1p @NikaInParis @Warchief Sanji D Goat @Hedfi @Juanpiz @Hamlette @Rumble @Mr. Anderson @Chaves @kekaro @Elder Lee Hung @ZenZu @Owl Ki @The White Crane @Fujishiro @Kurozumi Wiwi @SakazOuki @MarineHQ @Sentinel @SkySanji @The Legend @Ven437 @haxxor @silverfire @LANJI CUCKSMOKE @comrade @pg13 @notAfanboy @ImmaIvanoM @EmperorKinyagi @Albino 👑 @soupongo @Kurozumi mugiwara44 @GalaxyLevelShanks @park_min young @Roo @RyoQ @kyejames316 @moreha9685 @NotTommy @Sugoi @Jailer @U c 4 up da idly @Monkey D Theories @Rootbeer @JoNdule @Darkrai1381 @HeroesNZ @Garps tekkai @Tyki_Mikk @Heart pirate @Nidai_Kitetsu @Chrono @Cross_Marian @Cozy Sofa @DonWick @The DevilMaster @gz89 @Jackteo @AkainuTheGrimReaper @HellBlazer04 @Zaretball @MegaSpider @zzShinichi @Nadel @DarkWitch @Salah WG @CoC: Color of Clowns @Dark Knight Sanji @Konstantis @Luffy is the mc @GeneralP123 @BleakAsh @GalaxyLevelShanks @RyoQ @Bisoromi Bear @Kizaruber Eats @Kair0s1 @Zoinks52 @NAMELESS @Zoororo @Gol D. Bullet @Psychiatrist @Etzel Andergast @SaitamaSanji @BattalGazi @Djordje @Chaves @haxxor @Vanlax @park_min young @Blax Blah @Mr. Anderson @Buusatan94 etc etc