I did some maths on Ironclad and Enrage

And honestly, it does not seem as bad as everyone thinks it is.

I am assuming that by "average" level, it means that you take the mean of the levels on the team, aka. If your team has levels 6, 7, 5, 6 and 6, the average level would be 6 (6+7+5+6+6 = 30, 30/5 = 6). Now, let's take a look at the descriptions for Ironclad and Enrage.

ENRAGE: If your team's average level is at least 3 higher than the enemy's and you've taken 2 or more towers in a given lane, your minions in that lane deal 90% more damage to enemy minions.

IRONCLAD: If your team's average level is at least 3 higher than the enemy's and you've taken 2 or more towers in a given lane, your minions in that lane take 7 less damage from enemy minions.

Note that it says your team's AVERAGE level must be 3 levels higher than the enemy's. That means that if you take the mean of your levels and the mean of their levels, yours will be 3 higher. In order for that to happen, your team needs to collectively be 15 levels ahead of the enemy team. Let me demonstrate with an example.

Say Team A got stomped hard in lanes by Team B. For simplicity's sake, all champs on team A are level 6.

6+6+6+6+6 = 30. 30/5 = 6.

The average level for Team A is 6. In order to get the Enrage and Ironclad bonuses, Team B's average level must be at least 9. The simplest way to achieve this is if everyone on Team B are level 9.

9+9+9+9+9 = 45. 45/5 = 9.

Everyone on Team B is 3 levels higher than everyone on Team A, which totals to a 15 level collective advantage. And that's just barely scraping the Enrage and Ironclad bonuses. Now, let me ask you this - how often have you seen a team be collevtively 15 levels ahead of their enemies? Usually a losing lane will be 1 or 2 levels behind. In order to be 3 levels behind, you probably must have died at least 4 times or something, without getting ganked by your jungler. Not only that, you have to have taken two towers in the lane for this effect to kick in. That rarely happens during the early game.

Now, let's take a look at the other set of the minion changes.

MINION DAMAGE BONUS: If your team's average level is higher than the enemy's, your minions deal 10% bonus damage to enemy minions. If you've taken cumulatively more turrets than the enemy team, damage is further increased by 10% for each turret you have over your opponents.

MINION DAMAGE REDUCTION: If your team's average level is higher than the enemy's, your minions take less damage from enemy minions equal to (tower differential x level differential) + 1. This number can't fall below 1.

Now I have to admit, at first glance that sounds pretty scary. However, if you crack the numbers those changes are honestly not that bad at all.

Let's start with the minion damage bonus. If your average level is higher than the enemy's, your minions deal 10% bonus damage to the enemy minions. But, what does that really mean? Well, using the wiki I pulled some stats on the minions.

Meele Minions start with 12 damage, which increases by 0.5 every 90 seconds. At 15 minutes (900 seconds), minions do through 9 damage increases because they spawn at 90 seconds. Therefore, meele minion damage increases by 4.5 (0.5 x 9) to 16.5. With the minion damage bonus, this means that meele minions deal a whopping 1.65 more points damage to your own minions (17 x 0.1 = 1.7 increase in damage).

Caster Minions start with 23 damage, and it increases by 1 point every 90 seconds. So at 15 minutes they actually deal 32 points of damage. With the minion damage bonus, this increases by 3.2 points of damage (32 * 0.1).

Now, do those figures sound particularly impressive to you? I mean, sure, they do mean that your minions will push on their minions more, but it's not like every lane will suddenly have 40 minions super-clearing all of your waves. I would do more maths on this, but I'm not sure whether the perfentage bonuses for the minions stack multiplicatively or additively. The wording seems to suggest the former, but it could swing either way. Still, the minion changes don't seem that drastic at all. It seems to me that it is more of a shove towards stopping losing teams from turtling for 30 minutes and winning off of one sloppy teamfight. The bonuses (plus Enrage and Ironclad kicking in) only really start to get drastic when you're getting stomped hard.