Not to be contentious me being a sinner I don't read Srm much, that would be like trying to educate pork.I did not realise it did not actually prescribe jhatka, but if it says don't eat halal ,by law of deduction it means slaughtered in the opposite way.
I don't think so. Imagine feeding 25 million Sikhs minus vegetarians worldwide by jatkha. Expensive because it is inefficient. High overhead for butchers.
On a more serious note: If one understands how the halal slaughter is carried out, how it is prescribed, then almost any other method would qualify as "not slaughtered in the muslim way."
Any male may conduct the slaughter. There is no requirement of a clean or finely sharpened knife. With each animal killed the invocation "Allah Akhbar" is given. In modern practice, the abatoirs recently used for kosher slaughter may be preferred or not. Allah Akhbar is the central feature.
The argument gets waylaid by the assumption that "animal suffering" is to be avoided. I don't know if that was what was on your mind orn ot. Actually it is the "ritual" of halal that was to be avoided. Much like the SRM states that Sikhs should not worship at musim graves.