selenium grid crashes due to increase in hub queue

When i am trying to run 1500 scenarios in multiple browsers(175 Available browsers). selenium grid sends the pending test cases to queue and the test execution freezes and crashes.
is there a way to configure the selenium grid so that the test cases doesn't go to grid queue.

My Testng XML:

<suite name="TEST" verbose="1" parallel="tests" thread-count="175">
<test name="TEST1" parallel="instances">
<classes>
<class
name="test1" />
</classes>
</test>

<test name="TEST2" parallel="instances">
<classes>
<class
name="test2" />
</classes>
</test>

also is there any way to run tests parallel from both tests. When ever i am trying to run the tests are running only from test1 and nothing from test2. I need tests to be picked from both the tests randomly.