is it correct

According to some research, 10pm to 4am is the time whereby the body will heal itself most. While it is possible that the body will repair itself when you are sleeping in other timing, but it is not as effectively. So if possible, squeeze your 2hours of night rest within the time frame.

My answer is: absolutely not! You should start sleeping more, it is good to your health if you sleep a lot an night. Sleeping is the time when you rest, and renew your energies to continue without any problem, and if you don't sleep enough, you'll have health problems in some few years. So, is your choose if you want health problems or not.

You progress through different "stages" of sleep. Your body needs to go through deep REM sleep on a daily basis, which takes hours to get in to. So one sleep time of at least 5+ hours is needed. Taking short naps to refresh your self and brain will be needed through out the day if your main sleep is short. It is about getting a good amount of the deep REM sleep more so then total number of hours slept. But the shorter amount of time you spend in that deep sleep will result in needing more sleep overall.

As far as I know, sleep is the time where your body takes a "time out" to heal itself. Doing this during the day or at night, it should heal the same. Sleeping only two hours at night may lead to an erratic sleep schedule, but as long as during the day you catch up to about 6 or more, I think you'll be okay. I'm not a doctor though; maybe someone else with more medical knowledge can help.