Troubles with patching another mod

[XDSane]

I have no modding experience. Trying to change ascend/descend speed of pegasuses from https://mods.vintagestory.at/pegasus
I've located required values in entities/wildpegasus.json. Edited them and it works how i intended. But i was told that i need to make a patch mod for this changes could be applied on a server. Now my patch works only partially: it did changed vertical speed when pegasus also moves forward, but it does nothing when pegasus is hovering. 
[
    { 
        "file": "pegasus:entities/wildpegasus",
        "op": "addmerge",
        "path": "/behaviorConfigs/jaunt:gait/gaits/8",                //this patch0 is for hover mode, in original mod this section does not have ascend/descend keys, but i added them when i was testing in 
        "value": { "ascendSpeed": 9, "descendSpeed": 10 },    //singleplayer world and it worked
        "dependsOn": [ { "modid": "pegasus" } ]
    },
    { 
        "file": "pegasus:entities/wildpegasus",
        "op": "replace",
        "path": "/behaviorConfigs/jaunt:gait/gaits/9/ascendSpeed",
        "value": 20,
        "dependsOn": [ { "modid": "pegasus" } ]
    },
    { 
        "file": "pegasus:entities/wildpegasus",
        "op": "replace",
        "path": "/behaviorConfigs/jaunt:gait/gaits/9/descendSpeed",
        "value": 20,
        "dependsOn": [ { "modid": "pegasus" } ]
    }
]

JSON Patching tutorial (https://wiki.vintagestory.at/Modding:JSON_Patching#AddMerge_operation) says i need to count sections starting from 0 and from last label. Last label is "gaits", hover section is number 7 and glide section is 8, but if i change path to point on 7 and 8 - patch bugs out. 

Please, i need help