long time ago i once read on what lab conditions manufacturers use to define their silicon amp rating. it was a crazy unrealistic thing as i recall, something like emersing the mosfet in some sort of jelly and what not. no matter what the current ratings or how they are used (switching, continuous) in a realistic environment.. at the end of the day there are three limits for how much current/temperature you can use.
1. the junction temperature needs to be 25C less than datasheet limit or you risk thermal runnaway (here is where the 175C Tjmax can come in handy).
2. the rate of change of current has to be within the mechanical limits of the device (i don't think there is a datasheet parameter for this, but it speaks to the internal bond wires flexing and breaking off), this is one of the key factors that defines a "good" manufacturer. its not a thermal problem because the current comes & goes too quickly. if you have many devices in parallel, say more than 4, and do not manage the transient current sharing at ON/OFF this risk of mechanical failure can be a problem ("solved" by China controllers by switching very slow and putting a huge fan on it).
3. the delta temp between heatsink and junction temp has to be some max value or less. 40degC comes to mind, but that's just an old memory. this is another form of mechanical failure but not the wire bonds, some other part of the mosfet.
the above are just rules of thumb, you can push a device beyond any of the above but it starts to take away from the life of the component.
i suspect item #1 and more likely #3 to be something for investigation in your application but if you can get 200Amps while staying true to the rules above with only two devices in parallel then you're good to go.