Are you talking about magicka or stam? And I am assuming PvP?

There are a lot of major advantages to clever alchemist that cause it to be used to widely (I use it on my build):

1. Because it is craftable you can use it to get the exact armor weights you want plus you don't have to do any gear farming.
2. Its bonuses provide both spell and weapon damage so it is useful for both magicka and stamina builds.
3. It provides tankiness (health) which is much needed in a proc/destro ult meta while still providing insane burst capabilities.
4. As you speculated in your post, it is not really possible to reproduce the weapon/spell damage obtainable through the Clever proc. And 15 seconds is quite a long time to have that buff.
5. And most importantly, it can be used with 2 monster pieces and another 5 piece set even when used on a build with 11 slots (e.g. destro/resto or 2H/Bow builds). The weapon/spell damage carry over even when the 5th piece is not present on that bar. So you could have a setup like 2 Skoria, 5 Spinners (with destro staff being spinners) and 4 Clever on your offensive bar. Then you can make your resto staff the 5th Clever piece. Go to your back bar and pop the potion giving the bonus then switch back to your front bar and the bonus "carrys over" to your 2 skoria, 5 spinners offensive bar.

That being said, there are other options for high damage. But I would need more information about your build to make a recommendation.

If you don't mind using "proc sets" then those will give the highest burst on a stamblade. Something like 2 Velidreth/Selenes + 5 viper is very bursty. Especially if you are running duel wield with another 5th piece set. You could add in another proc set like Widowmaker or another good damage set like Spriggan. Or, if you want to have sustain too, Eternal Hunt is an amazing set and is craftable. A heavy attack + incapacitating strikes + a couple of those procs going off can essentially one shot somebody. Just be prepared to induce a lot of rage.

If you don't want to use proc sets then it really just comes down to stacking your max stats as high as possible. Prioritize weapon damage first , then stamina. Weapon crit and weapon pentration are also important as is your crit damage multiplier to some extent. Sets Automation, Spriggan, Agility, 1 piece Kena/Velidreth give great max stats. Typically 10.5 stamina = 1 weapon damage for purposes of calculating an ability's damage. But it takes about 40 stamina = 1 weapon damage for the actual weapon light/heavy attacks which is why weapon damage should be a focus.

A very good stam set I use it bone pirate tatters. That set takes care of your max and recovery so you can choose a pure DPs set, I use black rose but night mother's embrace looks like a nice pair.

I guess I put this in the wrong section sorry.