Does having reinforcements arrive up the enemy rating?

Every time I have reinforcements from the transit tunnels arrive, the enemy gang shows up much stronger and wipes my clock, but when I don't have the reinforcements arrive the battles seem fair. If having the reinforcements just makes the fight harder, then it seem better not to use them.
That's right, at the moment, the reinforcements are also added to the strength and thus, the enemy gang is stronger.
That's already discussed in other threads.
For example here: