The factions that have no FRP- Ostheer and Soviets- have something called Halfracks. Not only are they mobile sources of reinforcement, and also means to transport troops, but can reasonably hold their own and support nearby squads.
So really, time it takes to walk back and forth from base versus a faction that has FRP is unfair, as non-FRP factions has methods to move faster, and not just from base after a retreat, too.
FRP is a way easier to use, needs no micro, does not eat pop cap. You simply do click-click.
With HT you need to micro HT behind your troops all the time and at some point you gonna lose it. Let's say, schreck blob is coming from side, so you need to switch maxim, get cons behind cover, move HT behind maxim. That's damn way more of micro, instead of click retreat a go back in few seconds and at some point so won't be able to control efficiency crew weapons, at guns, cons, tanks and ht.
Still if I retreat blob, how many HTs I need to get back to the same point? How much more micro I need when compare to 5 volks blob mass retreating and mass coming back in next XX seconds?
Plus, if I get under suppression it's over. HT won't help me.