But if Texas was not a slave State then is probable that they wouldn´t fight against the Mexican state, one of the biggest, if not the Biggest Reason, that Texas declare his independence of the Mexican Estate was that Mexico Forbid the Slavery in 1829, and have strong centralist policies that will end the slavery de facto, and not just de jure in Texas.
I think that a careful review of the facts on the ground in Mexico in the 1830s makes the bolded statement above improbable. Were it true, Mexico wouldn't have spent much of the 1830s attempting to put down revolts between the Yucatan in the south and the Rio Grande Republic in the North and more than a few places in between.
Here's a source of information that does a good job of explaining and contextualizing the Texas Revolution,
here.
While slavery was an aspect of the revolution, as can be seen in the above referenced article, it was hardly alone, and wasn't, in and of itself, the cause majeure of the Texas Revolution. When I look at the causes of the Texas Revolution as seen through the lens of the people who participated in it, I would rank them in order of importance as follows: Abrogation of the Mexican Constitution of 1824 by the Centralists under Santa Anna (the siete leyes), suspension of Anglo immigration at a time when land costs in the US put land-ownership out of the reach of the many (of course, Jacksonian views on banking were, IMO, partially to blame for the lack of credit in the US, which put the squeeze on many homesteaders, and Texas was a viable alternative for cheap land) and I would couple with that the nascent idea of Manifest Destiny as part of the second reason. The next subset in relevance would be a catch-all of racism and slavery that was endemic at that time.
My point is that as reasons go, slavery was down the list as causes for the Texas Revolution.
I'm not trying to minimize the role of slavery in the years of the Republic. Even a casual look at the Texas Constitution reveals the fingerprints of the slavocracy of the South. But that's not the same thing as looking at the causes of the revolution. A quick look at the fatalities of the Alamo reveal that fully 1/4 of the defenders were not born in the United States.
For the sake of the OP's speculation, let's say that in the years between 1821 and 1836, we increase exponentially the number of Irish and German immigrants, and expand the number of "free soil" immigrants from the US, you're still likely to be dealing with a central government that is tone-deaf to settler's rights, representative voices, taxation and tariffs, and a Catholic church that was beholden to the interests of the centralists. That proved to be a recipe for political and social unrest throughout all of Mexico. I don't think one can reasonably expect a Texas with different immigration patterns to not revolt. It's worth looking at the actions of European born Texians IOTL to see that they happily joined their neighbors from the American South in an effort to throw off the yoke of Santa Anna's despotism. What you categorize as "strong centralist policies" I would term as the stuff that caused Mexico to stay in a constant state of disarray between 1830 and 1848. Were it not so, I can't imagine that Mexicans like Lorenzo de Zavala would have thrown their lot in with the Texas revolutionaries.