The next feat we have to say is that the Supreme Kai of Time had forbade Xeno Goku from turning into an SSJ4  :

That's due to the fact that the last time by the process of turning into one, he threatened the existence of the timelines in SDBH : Arcade.

Now let's see the amount of hax that Xeno Goku has that can make this fight even more unfair than the fact that his base is essentially Hyperversal (14D).

Xeno Goku's hax are :

Purification :

Immunity to Space and Time manipulation due to the fact that it was stated in the first Dragonball Xenoverse - more specifically by Beerus in Battle of Gods - that beings with God Ki are immune to the effects coming from beings that have demonic/dark ki.

Possibility Manipulation :

Damage reduction :

Time Manipulation and Pocket Dimension Creation :

Time Freeze :

Wish Granting via Summoning Shenron :

Power Nullification via Keysword :

Life Drain and Life Damage :

Reality Warping :

Now before anyone says that the last two aren't Xeno Goku's Hax, remember that in the SDBH Arcade Game you're allowed to use powers from other cards whilst customizing your deck :

Now after talking about base Xeno Goku's scaling and Hax, let's talk about his speed.

His speed is tremendous, easily Immeasurable Speed due to scaling to the Dark Dragonballs that were able to fly through time and space.

Or via beating so many Hyperversal (14D) beings that easily since in Dragonball increases in strength and increases in speed have a perfect 1:1 ratio according to Vegeta's statements in the Namek Saga :

In case I didn't explain what's immeasurable speed, let me explain real quick. Immeasurable Speed is a speed where characters aren't bound by linear time.

How does it compare to other speed tiers ?

It's simple.

Infinite speed means that you're able to traverse an infinite distance in finite time. In other words in the speed equation u=x/t where as x is denoted the spatial distance in infinite speed we have x=♾️

Inaccessible Speed means that you're able to traverse an infinite distance in zero time.

In other words in the equation where we have u=x/t where as t is denoted the time of travelling, for Inaccessible Speed we have t=0.

Now let's finalize the scaling for Xeno Goku :

Scaling/Dimensionality : Hyperversal (14D)

Speed : Immeasurable

With a few words the winner of the fight is...

Xeno Goku!!!

Difficulty : No to Negative Diff (Bro could literally sneeze Terra 2 Saitama away if he wanted to and it still would be a valid winning condition 💀)

If we count their personalities, they wouldn't fight since their ideals of using their powers in order to protect others in need are pretty much the same.

They would undoubtedly spar from time to time, but even holding back Xeno Goku - much to Saitama's frustration - would still win 10/10 sparring matches, albeit there's the fact that Saitama had found someone to push him to new limits and maybe a good friend to give him a reality check if necessary when Saitama thinks he's too strong for his own good.

In the end of all, they'd probably be best friends or rivals instead of enemies.