"tricky to achieve" is correct and usable in written English.
You can use the phrase when something is difficult to accomplish or complete. For example, "Creating a successful marketing campaign can be tricky to achieve."
It would reinforce the group's credibility, though it could be tricky to achieve.
Providing an assortment of these is crucial to the charm of any meal and tricky to achieve without meat.
Creating such images, and that of a Plasticine couple dancing atop a spinning record, is tricky to achieve, requiring improvisation of a different kind.
It is perceived as politically risky because such a huge number of people would be seen as winners and losers, making it tricky to achieve political consensus.
Negotiations on the liberalisation of trade in services may prove as impossibly tricky to achieve as a deal on farm and industrial goods.There are other indications that major trading powers do not expect the Doha round to be a success.
It is tricky to achieve very higher char conversion (especially higher than 85%) in the gasification reactor we studied, so this reduction of impact of the char conversion is very important.
So maybe the company is approaching the point at which further advances are trickier to achieve.
This means unemployment needs to rise, which makes a soft landing trickier to achieve.
Determined as she is, Napravnik's successes would have been far trickier to achieve had she not enjoyed the unalloyed support of her family.
Now that the financial crisis has burst the real estate bubble in Britain and sunk the formerly high-flying pound, the legions who crossed the channel are finding it trickier to achieve their idyll.
Now that the financial crisis has burst the real-estate bubble in Britain and sunk the formerly high-flying pound, the legions who crossed the English Channel are finding it trickier to achieve their idyll.
