hi all,
I start from the bottom, with comments and possible explainations about mine and your writings.
I noticed different thought among the ones answered here.
The argument is pretty simple and fully argumentable.
If you take it alone, in a good mixed metagame, CoW itself is good and can prove to be solid protecting your own mana base.
The problem arise only when you try to put it in a SLOW deck, with a SLOW friend ( Stripmine ) and with FAST&FURIOUS opponents.
The nuts consist on a CoW with a tutor for an answarable Stripmine.
You need a full turn in order to POSSIBLY kill one of his lands.
If he build the deck in a good way, you have to protect yourslef from his OWN subsequent turn.
He can build a stable mana base simply pulilng out moxen and without missing a land drop.
They can Walk into another turn and simply neglect your own effective denial recursion for another unexpected turn.
On the other hand, if you have CoW out, you can be tapped out and with a single FoW in hand.
Is it STRONG? Yes.
Is it NEEDED? No, especially because the deck consist on a crucial COOL way to optimize a "paradenial" strategy without the need of Maindeck CoW.
Titan kill opponents lands faster than CoW+Strip and Stripmine can be tutored and recurred when needed, in order to slow down a bit opponents.
Is it BETTER than a fully and stable Strip recursion? Of course not!
Is it FASTER than the previous described game situation and is it less clunky? OF COURSE YES!
Which is the WORST among the problems a good 4ccontrol.deck has? Be predictable, static and ... uhm... SLOW!
I added as much control elements I can choosing them ONLY among the ones that effectively DO SOMETHING when I resolve them.
Am I going to put in it DSC and CoW? HELL, NO!
Why? Because you have to sometimes tap you out with some amount of mana.
Has this mana development a cool effect once used for them? NO!
Are they game ending the subsequent turn? HELL, NO!!!
Are they predictable and easily answerable? HELL, YES!!!
Sadly... I have to regret the use of CoW, even if I miss it sometimes, when the game slow down and when I have random of subpar opponents.
Maybe, a single Tutorable CoW can be added in side, for stability reasons.
You are true about the possibility to lose one or two lands when hitting with Titan.
On the other hand, I have to describe you the game situations WHEN, I have to abuse of Tinker as fast as I can and for porpouses FAR different rather than killing people with 7/10.
PitchLong, TPS and GoodControl decks have EXTRASTRONG mana bases. 2x Swamp or Multiple Islands and a lot of fetches, make my stripmine a null denial effect and shaman only a noisy man, rather than a Bomb. Against them, you have to put out balls and put a fast Tinker. Is DSC the right way to deal with them? Of course no. They can bounce it WHENEVER they want, possibly even needing to tutor for a solutions. It is hit by ANYTHING Combo and ControlCombo decks, usually pack in. For these reasons, I have to fetch for Islands, wait their first or second lands drop, put out a Tinker and STEP THEM BACK OF 2 TURNS IMMEDIATELY, stealing a Swamp/U.Sea and an Island in a single shot! Is this game over? Of course not, but you are heading the game from a superior point of view! You negate them the possibility to abuse of stable mana fonts. A resolver Titan, translate itself in at least into two times walks for you, while DSC would have been nothing more than a noisy fly to bounce back.
It is perfect to deal with UW and UWB Fish decks too. They need their own lands FAR MORE THAN you. They have to resolve M.Mage and Confidants, both colors out, they will lose ALL their lands in a single kick and they have to wait for other mana fonts from a deck with an unusual low mana count. If they don't keep a StP or a Bouncer in hand, they suddenly LOSE the ability to fast deal with 7/10 that instantly can be compared with DSC, when racing people without mana at their disposal.
Of course, more the game went on, and far more are the possibility that you have had the need to resolve both Shaman and Confidant, doubling the possibility to lose a Volcanic or an Undergroound. The deck, on the other hand, is STUDIED to pretty well perform with 2 or 3 mana fonts on board. Confidants and Repeals and Brainstorms are FAST way to search for Fetches and Fetches themselves will protect you from losing your own lands: simply don't search for lands as soon as they are put on board, especially if you are optimizing your plays to resolve a cool TinkerForTitan.
Feel free to add DSC in that slot, but my reasoning are far wiser than they can appear to a quick glance.
I usually play with DSC main and Titan on board in almost ANY other deck.
This version of 4c-c can support the change that I made from side to main: you would enhance the strenght of a "so-so" spell ( such as Tinker can be considered in a pure control deck such as this one ).
As i previously state, I want things that can functions by themselves.
EtW and Teferi are, IMHO, good replacing for Tinker and Titan.
Even Meloku, can be tried in Teferi Slot, too.
Those cards, are really good when you are back and you have to win.
Feel free to exchange winners configuration as much as you can in order to find the BEST configuration.
At now, I would keep Timetwister maindeck, I will keep B.Wish for *alternate winning conditions* and I can think to abuse of only two other slots for additional winners.
If you think about HOW the deck usually perform, Shamans and Confidants usually bring opponents down in life and additional kill conditions are *incidental*.
If you are going to steal some lands and some artifacts, if you are going to draw cards freely, THEN, you can even win your own Penis! ... especially if opponents are girls

On the other hand, both Meloku, Teferi and EtW are cards worth trying.
I tested them in different deck and I LOVE THEM ALL SINGLEHANDLY.
For this deck, I simply choose to play the one that, IMHO, seems to HELP more on establishing control, with a little mana development ( that is the BEST part of my argument, even if it is the latter: Tinker cost 3 and I have fewer mana fonts than other 4cc decks).
Hi man, nice to be the *good old fashioned lover boy* for you all this time

I would put a bit more emphasis on Titan and Crushed Lands.
I usually don't pull out more than a single Island and ONE Dual land during the first two initial turns.
When you are playing with keeper, you would recognize HOW STRONG would be not to quickly act proactively with lands, because the deck can offer NASTY mana situations, especiallly UNEXPECTED ones. If you are wise, there are really few possibilities that a resolved Titan .............................
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to be continued