Are hashocean, hashflare and hashnest are from the same company?
No they are not the same. Out of the three, I have heard only about Hashnest and I know that they are maybe even the only legit cloudmining service that still pays.
Other two might as well be the scams since this cloudmining industry is about 95% scams anyways.
And in the rest 5% you will not (or never) reach the ROI. The conclusion: 100% waste of time and money until someone prove the opposite.
Even in the Hashnest you will reach the ROI very hard and if you do, it will take you a very long time. It's not just about buying some mining shares. You need to know when to buy, you need to follow the difficulties, hashrate and the price.
So for the newbies, all of this can become very overwhelming since their experience in mining is non-existent. The best is to stay away completely from cloudmining.