Razor building 
Vanguard! So I though I would offer some reasonable substitutes for these Items.I still implore the use of a stout shield in early game. So it's then 1,975 gold to build vanguard.
Vanguardlet's say I'm a lvl 6 
Clockwerk by the time I build vanguard:Pre vanguard:
Armor: ~4 armor (probably have an iron branch)
Stout Shield: 53% to block 20dmg. (due to pseudo random distribution)Expected dmg reduction:
19.4% dmg red. from armor
assume attacks are for 80 dmg.
With stout shield and Armor I'm stopping an expected value of 24dmg per attack of 80 dmg.
Remember that the shield stops damage before the armor, so it's not really adding an extra 20 dmg reduced.
After
Vanguard (1975 gold later)Armor: ~4 armor
Vanguard: 70% to block 40expected dmg. reduction per attack of 80 dmg: 38dmg
MARGINAL BENEFIT OF SPENDING $1975:
14 dmg reduction per hit of 80 dmg (as damage goes up this number that vanguard adds, gets lower and the armor becomes more effective [relatively])
+250HP
+6HP regen
Alternate vanguard build (2253) (i had an iron branch)
stout shield :53% to block 20 dmg.
Mekansm: +95 health, 5.7 armor, +65 mana, +4 health regen, and an activated ability that increases armor and restores health.
armor now=~9.5 armor
Expected damage reduction per 80 dmg.== 35.5 dmg stopped (2.5 less than vanguard) (will stop more if there is more damage and as agility increases with lvl)
So For 278 more gold I get:
about as much dmg. reduction.
-2 HP regen
-155 HP
An Active that grants +2 armor for 25 seconds to you and allies
An active that gives +250 HP
An aura that gives +4 HP regen to allies
What to take away from the math:
Vanguard is not an efficient means of damage reduction.
Armor Items provide a more economic answer to damage reduction.
Mekansm beats Vanguard on even melee heroes! Mek dominates Vanguard on heroes like 
Viper and Razor.I'll have more Item comparisons coming. Please Give feedback if my writing is too hard to follow. I can clean it up to make it more clear.
And to clarify: Building two meks is a waste of money because the auras don't stack, and there is a cooldown time on receiving the active. (so if two teammates use mek within 25 seconds of each other, you wouldn't get healed a second time.)
I recommend having support focus on wards, sentries, dust. They can build a casual
This isn't so much meant for Hard the carry. But for semi-carries. Semi-carries are less likely to be away from the action in mid game.
Okay, I agree. Especially on Heroes such as Razor or even Melee Semi-Carry/Supports like Clockwerk. They will be ganking more so Mek's effectiveness increases.
Okay, I also half-agree, but when still low-ish level (5-10), a hero such as Razor will need all the mana he can get to effectively gank. Other non-int semi-carries the same. Having to cast a Mek might eat his mana too quickly.
But I want to reiterate on my take of these items. I tested a Mek on a few Agi-Semi carries, and surprisingly it did work out. Sadly in Pubs there is always a support making a Mek without checking if its already made so there were necessary stacking, but I think in many situations the Mek is a good alternative.
Hard carries like
This isn't so much meant for Hard the carry. But for semi-carries. Semi-carries are less likely to be away from the action in mid game.
- For Mekansm to be viable, you need to be able to use its Active, which costs 150 mana. Most Str and Agi carries seldom has the Mana pool for that, and the mana-cost makes it less viable for anti-harass or farming in the jungle.
The math shows Mek being equal to Vanguard without the activated ability. so you wouldn't need to use the ability until a team fight. and it has constant HP regen like the vanguard.
Nicely put out with stats and things.
Comments :
- For Mekansm to be viable, you need to be able to use its Active, which costs 150 mana. Most Str and Agi carries seldom has the Mana pool for that, and the mana-cost makes it less viable for anti-harass or farming in the jungle.
- Mekansm doesn't stack, and considering its better on a Int Support, if you get a Vanguard, the two will stack giving you even better bonusses (which otherwise wouldn't be useful if stacked for nothing)
- You do see Mekansm on Int Semi-Carries such as Silencer or Destroyer, so your math doesn't lie.
- Mekansm's effects are team-wide, so placing it on a carry that will farm on his own for quite a while in the game will reduce its usefulness (considering that getting two Mek's are redundant)
I think you're forgetting that the support can always go for a Pipe, especially since Mek is also used on certain heroes like Meepo and Necrolyte.
Comments :
- For Mekansm to be viable, you need to be able to use its Active, which costs 150 mana. Most Str and Agi carries seldom has the Mana pool for that, and the mana-cost makes it less viable for anti-harass or farming in the jungle.
- Mekansm doesn't stack, and considering its better on a Int Support, if you get a Vanguard, the two will stack giving you even better bonusses (which otherwise wouldn't be useful if stacked for nothing)
- You do see Mekansm on Int Semi-Carries such as Silencer or Destroyer, so your math doesn't lie.
- Mekansm's effects are team-wide, so placing it on a carry that will farm on his own for quite a while in the game will reduce its usefulness (considering that getting two Mek's are redundant)