Actually, I think they're right with one thing: You should get 1 miner and 2 swords instead of 3 swords. By the time the first 2 miners come back with the gold, you will have barely started on your second swordwrath. Go for 2 swords and 1 miner, then use the 1st income to queue up the swordwrath production to 3. This way, you end up with 4 swords and 1 more miner in the same amount of time.
Now, reading through your post, you never said get 4 swords immediately, so that might just be the goal, not the method. I'll assume you know about the miner. Now, I have another problem. Most people will rush with an archer and a sword. You'd be at a disadvantage at any map longer than forest against this start. You might say you have 4 swords, but they usually rush you before you have even made your 3rd sword. Get what the problem is? They can simply kite you with the archer so you never get more than 3 swords while their army grows.
I shall assume, once more, that you have the micro to deal with this start, and that you only meant this strategy for short and medium maps. Of course, anyone with a good micro or good luck can easily beat back a sword-archer start with 2 swords.
Now, I have a probelm to set before you in your reply; this all assumes that they won't rush past the speartons to kill your magikill. Even if they don't have a shadowrath, 3 speartons can easily kill your magikill, even if it is behind speartons. If your speartons have shield wall, you won't be guaranteed safety; they can simply form up in a horizontal line and rush past your spearton wall (1 unit in front, 1 behind it, another behind the one behind the first unit, another behind the unit behind the unit behind the first unit, and so on). And assuming they're not smart enough to do this, you still have a major problem.
You'd have to both use shield bash (to keep enemies from attacking the mage) as well as use spells in a space of 5 seconds. If you can pull this off, you're at Wyzdom level micro, which means you might as well use a Wyzdom level strategy instead.
Also, one more thing; like many beginning players (and even some of the best players do it sometimes), you seem to assume that the enemy would be disordered or idle while you are building. There is one thing you pointed out (the allbow killing all your spears), but there are other things you didn't think of. What if the enemy turtles and giant masses while you're busy building your army? You got the meric too late to be able to harass them mid-game.
Now, another thing; you didn't consider the possiblity that they would get archers and kite your speartons. This could make problems for you, even when your allbow comes out. The aggressive turtle or luring is getting into a higher tier level than it was before, which makes your 6 speartons incredibly vulnerable.
When you have the first spearton, you should go and pressure them; the spearton would tank up any castle archer hits while your swordwrath kill their miners. Let the swordwrath die, if they must, because they won't be used anyway later.
Another suggestion is to get the allbowtross by your 3rd or even 2nd spearton; this would help against the archer kiting/ luring strategy.
Finally, I'd like to suggest one more thing. Ditch the speartons for giants. The giants are better tanks for allbows anyway, especially if they have giants or allbows themselves. If you want, you can even ditch the allbows for more mages or giants. The Mage-giant combo is pretty much the preferred endgame combo, except for perhaps shadow-allbow for some players.
The Giants are better able to stop shadows, stunning them for a few precious seconds while your mage gets out of range. Swords can't beat back a shadowrath in shinobi or a horde of enemies more than one rank deep.
