C# Combine two lists with nested lists into one using LINQ

I have two list of the following structure in c#. Each name in <> is a list. I want to join those two lists into one List<Server>. The following pseudo code displays two such lists and how the result should look like:

<Servers>                           <Servers>
+...                                +...
+-- Server A,1                      +-- Server A,1
|       +...                        |       +...    
|       +--<Maps>                   |       +--<Maps>
|           +--Map x                |           +--Map x
|               +...                |               +...    
|               +--<Times>          |               +--<Times>
|                   +--Time i       |                   +--Time l
|                   +--Time j       |               +--<Jumps>
|               +--<Jumps>          |                   +--Jump t
|                   +--Jump s       |                   +--Jump u
|           +--Map y                |           +--Map z
|               +...                |               +...
|               +--<Times>          |               +--<Jumps>  
|                   +-- Time k      |                   +--Jump v
+-- Server B,1                      +-- Server B,2

Result should be:

<Servers>
+...
+-- Server A,1
|   +...
|   +--<Maps>
|       +-- Map x
|           +...
|           +--<Times>
|               +--Time i
|               +--Time j
|               +--Time l
|           +--<Jumps>
|               +--Jump s
|               +--Jump t
|               +--Jump u
|       +-- Map y
|           +...
|           +--<Times>
|               +--Time k
|       +-- Map z
|           +...
|           +--<Jumps>
|               +--Jump v
+-- Server B,1
+-- Server B,2

I tried using full outer join with linq but the result was also not what I wanted, for reasons I didn't understand servers that had the same keys weren't matched and so I always had duplicates of the same server with different data. That's when I stopped trying to do it with linq and just used loops to merge the lists by hand.

The code below gives me the desired result list. For now I will use it until I find a better way to do it. Is there a simple/shorter way doing that with linq? Using lambda expressions?

  foreach (Server importServer in oImportList)
        {
            if (!CoreList.Contains(importServer))
            {
                CoreList.Add(importServer);
                continue;
            }

            Server coreServer = CoreList.FirstOrDefault(o => o.Equals(importServer));
            coreServer.Name = importServer.Name;
            coreServer.KZTimerVersion = importServer.KZTimerVersion;
            foreach(Map importMap in importServer.Maps)
            {
                if (!coreServer.Maps.Contains(importMap))
                {
                    coreServer.Maps.Add(importMap);
                    continue;
                }
                Map coreMap = coreServer.Maps.FirstOrDefault(o => o.Equals(importMap));
                coreMap.Jumps.Concat(importMap.Jumps);
                coreMap.Times.Concat(importMap.Times);
            }
        }