Stake Granularity in solana

Question

Hello Can anyone please explain why is stake granularity important in solana? and also if I change all the stakers to one single address my total supply varies significantly,any explanation for this?

pub const CREATOR_STAKER_INFOS: &[StakerInfo] = &[
    StakerInfo {
        name: "impossible pizza",
        staker: "uE3TVEffRp69mrgknYr71M18GDqL7GxCNGYYRjb3oUt",
        lamports: 100_000_000 * LAMPORTS_PER_SOL,
        withdrawer: Some("59SLqk4ete5QttM1WmjfMA7uNJnJVFLQqXJSy9rvuj7c"),
    },
];

pub const SERVICE_STAKER_INFOS: &[StakerInfo] = &[
    StakerInfo {
        name: "wretched texture",
        staker: "uE3TVEffRp69mrgknYr71M18GDqL7GxCNGYYRjb3oUt",
        lamports: 5_000_000 * LAMPORTS_PER_SOL,
        withdrawer: Some("HWzeqw1Yk5uiLgT2uGUim5ocFJNCwYUFbeCtDVpx9yUb"),
    },
    
];

pub const FOUNDATION_STAKER_INFOS: &[StakerInfo] = &[
    StakerInfo {
        name: "lyrical supermarket",
        staker: "uE3TVEffRp69mrgknYr71M18GDqL7GxCNGYYRjb3oUt",
        lamports: 5_000_000 * LAMPORTS_PER_SOL,
        withdrawer: Some("C7WS9ic7KN9XNcLsNoMvzTvbzURM3rFGDEQN7qJMWNLn"),
    },
    
];

pub const GRANTS_STAKER_INFOS: &[StakerInfo] = &[
    StakerInfo {
        name: "rightful agreement",
        staker: "uE3TVEffRp69mrgknYr71M18GDqL7GxCNGYYRjb3oUt",
        lamports: 5_000_000 * LAMPORTS_PER_SOL,
        withdrawer: Some("EDwSQShtUWQtmFfN9SpUUd6hgonL7tRdxngAsNKv9Pe6"),
    },
    
];

pub const COMMUNITY_STAKER_INFOS: &[StakerInfo] = &[
    StakerInfo {
        name: "shrill charity",
        staker: "uE3TVEffRp69mrgknYr71M18GDqL7GxCNGYYRjb3oUt",
        lamports: 5_000_000 * LAMPORTS_PER_SOL,
        withdrawer: Some("8CUUMKYNGxdgYio5CLHRHyzMEhhVRMcqefgE6dLqnVRK"),
    },
    
];