Multiple similar entries in ssh config

From the ssh_config(5) man page:

 Host    Restricts the following declarations (up to the next Host key‐
         word) to be only for those hosts that match one of the patterns
         given after the keyword.  If more than one pattern is provided,
         they should be separated by whitespace.

...

 HostName
         Specifies the real host name to log into.  This can be used to
         specify nicknames or abbreviations for hosts.  If the hostname
         contains the character sequence ‘%h’, then this will be replaced
         with the host name specified on the commandline (this is useful
         for manipulating unqualified names).

So:

Host XXX1 XXX2 XXX3
  HostName %h.YYY.com

To minimize the setup you can have a .ssh/config like this one

Host X01
    HostName X01.YYY.com

Host X02
    HostName X02.YYY.com

...

Host X01 X02 ...
     User my_username
     Compression yes
     Ciphers arcfour,blowfish-cbc
     Protocol 2
     ControlMaster auto
     ControlPath ~/.ssh/%r@%h:%p
     IdentityFile ~/.ssh/YYY/id_rsa

Host X01 X02 ... could be replace by Host * if every host have the following configuration

Simply use *

See man ssh_config:

PATTERNS A pattern consists of zero or more non-whitespace characters, ‘*’ (a wildcard that matches zero or more characters), or ‘?’ (a wildcard that matches exactly one character). For example, to specify a set of declarations for any host in the “.co.uk” set of domains, the following pattern could be used:

       Host *.co.uk

 The following pattern would match any host in the 192.168.0.[0-9] network range:

       Host 192.168.0.?

 A pattern-list is a comma-separated list of patterns.  Patterns within pattern-lists may be negated by preceding them with an
 exclamation mark (‘!’).  For example, to allow a key to be used from anywhere within an organisation except from the “dialup”
 pool, the following entry (in authorized_keys) could be used:

       from="!*.dialup.example.com,*.example.com"