This is a meme I am absolutely sick to death of seeing and it gets cites by people all the time as a reason that some downside or other of a unit is actually an advantage in disguise! The basic form of it goes like this:
“Sure, my pet unit lacks [insert quality here], but that's actually an advantage- it messes with the opponent's target priority!”
No. No. No. No. And no again. That is not how things work; you cannot just magically invert your qualities into being helpful to you when you have no counterargument.

The fundamental flaw here is in thinking that your opponents are so stupid they will make a mistake in targeting the wrong unit (with shooting or assault) because you made one of your models WORSE. You are trading raw functionality of the unit in game terms for what you hope is a complicating factor in your opponent's mentalization of the battlefield, and there is absolutely no guarantee that will affect them at all. Will they screw up and choose wrong? It's possible, but they might've done that anyways, so all you've really done is weaken yourself. You cannot meaningfully control your opponent's mental state- you can force choices on them (shoot the Solodin or the Fire Warriors?), but you cannot define the terms of those choices (what guns they have available) or how they will make them.

In short, you are trading the illusion of altering the enemy's choices for the reality of what the units actually do.
“But they could underestimate the unit and-”

And they could also have a seizure and die during the game, but I wouldn't count on that for your winning strategy. If you want to win, assume your opponents are competent players who will make good decisions and work from there- you leave room to take advantage of their errors, because yes, they will inevitably make some, but you do not ASSUME they will make errors in play.

“Yeah, but they're a really good distraction because they-”
Stop right there. Distractions are bad; a cute puppy walking by the table or a hot girl/guy or a sudden fireworks display are all distractions. Distractions are attention-getting but ultimately irrelevant to game play. What you want are threats- units that force the enemy to deal with them or they will cause problems for their plan by shooting, assaulting, or contesting important things. If all your unit can do is harass and annoy the enemy, it is a distraction. If, left alone, it can ruin their plan, it is a threat.
This is where the fallacy arises- when a unit ends up being shown to not be a strong threat, it gets played off as “well it's just a distraction.” Distractions suck. Threats are good. If you need something to distract the enemy from their plan, send a threat.