You may choose to skip installing your own colocation firewall because the host’s is good enough to tackle any threat likely to threaten your system. In my opinion, you should get in touch with the host and clarify whether he is indeed providing a firewall or just a bare-bone network.
If it’s the latter, go and configure your own
firewall and if the host is ready to provide one, do not overburden yourself and let go off the thought.
However, there’s flip side to the coin too –Some hosts’ colocation firewall may not be as good as their hosting firewall, so get the same clarified. Second, if you choose to have another firewall, your network will become painfully slow. Firewalls take time to scan networks and the more layers of firewall that you have, the slower your network will become. It’s the paradox you cannot escape.