Generally Kumho and Nexen are very soft tyres but as with most manufacturers they produce different variants for different comfort levels.
As a rule of thumb the more comfortable the tyre more softer and stickier (grippy) it will feel but would jave a horrible lifecycle/longevity, 40k kms if you're lucky and 60k if you're pushing it. Compared to this my last michelins still had 30% tread left at 92k kms even with dry rot and 4.5yeara of service they did not lose grip and side walls were still soft but they were very noisy.
The energy savers or ES series in all manufacturers will have very low rolling resistance this equates to the presumed loss of grip when in-fact it was never sold as a grippy tyre in the first place. ES will and should generally last quite longer than advans.
Also why don't you opt for advans instead of ES if you wanted more grip. Me personally, love to corner hard even on the shiny roads of Lahore and up the mountains I had zero instances of loss of grip, although Dunlops on my other hatchback would skid around like crazy despite being newer..
What I think the issue here is your irrational (sorry for being harsh on this) comparison of a fuel/energy saver tyre with a performance tyre - both are doing their job just fine. But the ES will last you much longer and saves you enough fuel to pay for itself whereas the street racer tyre will be gone in half of the duration.
