well...Maybe I need to spend more time with KW but the reason why I like tigrar over KW is because of his fireball and flamethrower.
The gaps in strings into flame I can compensate by making them fear punchwalk. Once the fear of punch walk is confirmed, the flame becomes a pretty viable tool. Especially in the neutral. If it is blocked I'm at +12. f3 is 16 frames, 4 is 16 frames, f4 is 20 and d4 is 9. My d4 is free on hit or block so they have to respect that. my d4 is +19 on hit and on block punch walk is free.
On hit just just have more options. If they hesitate to block my d4 then it opens up other things like f4 and the knockdown to the corner.
Flame is also super meaty and great for stuffing wakeups and leaving you at super + frames again. If they are blocking up close to I can sneak in command grabs more easily. All that to say...flamethrower is pretty good. I also use it to stop run ins sometimes.
his fireball is super good. 9% on hit and super tough to jump over. Surprising good at winning trades and forcing your opponent to walk and neutral crouch. When they start to walk and neutral crouch, your low fireball becomes useful. If they block it they get pushed back and you can continue zoning.
Also the more worried they are about getting through your fireballs, the more often your stomp will hit them.
I don't see the spacing options being that similar at all to be honest. Getting the extra damage is nice but we talk about how useless his fireball and normal ground pound are?
Combine ground pound and the fire ball in KW, then you get something which is not to be trifled with. As i said before, ground pounds have insane recovery even on whiff, lower Goro's hit box (even most projectiles can whiff, giving Goro the win on projectile wars, although it requires a bit timing to do so) plus the fact that after a successful ground pound, if you dont want to spend meter for ex gp, you can check your opponent with a fireball or even another ground pound. If they get hit by gp, and start jumping forward you can check them with chest lunge. Ground pounds are awesome for full screen as well mid screen checking. Its scary.
Tigrar is good, but the flame breath gap after a blockstring can be seen from a mile away, plus it can be low profile by many characters in the game, if not all. The threat of pw cancel is there, i agree with you, but still i dont think its enough to switch over to tigrar. KW can easily check zoners as well. Goro in general has issues against characters with a teleport, although sometimes i have stuffed teleports with ground pound (have to be a jedi to do that consistently though).
On hit every var of Goro has many options. Free poke checking, sg, pw (duh), throw, 11 21 frame traps etc.
For stuffing wake ups you can also do f3 pw. Good damage, wall carry and opponent is at your feet and at the corner 99% of the time.
Also why use the low fireballs, when i have f3? Great range, excellent active frames, most of the time it will AA if opponent jumps from mid screen range and ofc can be canceled to pw, or you can pseudo cancel it to sg if your opponent respects the pw cancels too much.
All those things, combined with the damage KW can pull off, make him scary, like, real scary IMO.