A short starter is needed to start balls & patches I use in the big bores.
In the small bores, like my .36, I can start a .022" denim patch (crushed hard, measurement) patch with a 350" pure (as pure as we can get- X-ray room wall sheeting) with just a choked up rod.
I have even loaded my .40 with the same patch and a ball that is .002" LARGER than the bore, without using that rifle's short starter.
However, I've been using a short starter since 1972 & I see no reason to quit now.
I have 0 IE: ZERO problems loading with a short starter and dare say I can load faster with one than about 99% (OK maybe only 98%) of the lads on this site can with just using the rod & a thin patch. I do not get accuracy that satisfies me, if I do not use the patches required to give me that accuracy. Those, in hunting calibres, requires the use of a short starter.
Some rifles, as in those with wide grooves and narrow lands, allow very tight combinations that do not NEED a short starter, just that using one is second nature to me, thus I use it with all rifles and my smoothbore.
About the combinations - we up here in the smokey North part of BC, like to use a ball that is approximately .005" smaller than the bore. With that ball, we use a denim or ticking patch, that runs .022" to .02235" compressed hard, in calipers. 10 ounce denim works well. I use 12 ounce in my .69 with a .684" ball. I measure 12 ounce at .030" compressed with the calipers and .025" with my Mitytoyu micrometer. since I ran out of 12 ounce, a buddy gave me some 14 ounce he bought by mistake. I now use the thicker stuff - yes - you Have to WANT to make it fit & that means hitting the starter knob with a "heavy" hand. If you use enough strength, it does not hurt. If you nave to hit it more than once to get it into the muzzle, you did not hit it hard enough the first time and you will wear yourself out, ie: sore hand.
We have found this "Formula" or combination shoots well in every rifle we've tried it in - those rifles will run close to 100 or perhaps over that figure- BUT- it is every one we've used it in.
I will also state, NO - it is not hard to load these - my daughter caught on loading her mom's .45 rifle with a .445" ball and .022" patch right off the bat after watching me load the first one as a demonstration. She had no trouble for the rest of the day's shooting, perhaps 50 shots all together.