Riflemen and Grenadiers have exactly the same reinforce cost in proportion to their build cost per model.
If you're losing 4 riflemen while your opponent lost 3 Grenadiers, your opponent pays less MP to reinforce because they OUTPLAYED YOU. They used a unit which costs 6/7 as much to inflict 112mp of damage vs 90mp of losses.
The amount of bleed you suffer is based on the engagements taken, how well you play those engagements, as well as the bleed tools your opponent has.
Sure, RNG plays a significant factor in this game, but since you struggle all the time, the common factor is clearly your inability to use infantry.
What you say doesn't make any sens in a real game. Grenadiers are cheaper to reinforce because of old game design mechanism USF infantry > Ostheer Infantry. Is it still the case today? Honestly I don't think so when I look at my games or best players on twitch.
When you see Ostheer building almost every games 1 HMG + 4 gren vs USF, it is because Grenadiers can definitively duel riflemen and win in many situations. Remember a year ago or so, 4 gren was a suicidal strategy, you needed HMG sometime 2, mortar and tech fast to 222 and Pzg in order to do your transition into late game. Today you're happy if you see a pak as USF.
Grenadier spam everywhere is the reality today which contradict your saying.
The second point which also contradict your saying is that an upgraded grenadier squad down to 1 man is vastly superior to an upgraded riflemen squad down to 1 man as well. Thanks to the LMG42.
Now I don't think grenadier stats are the problem here, I still think Ostheer (and OKW and UKF once align to other factions) should lose all or some of their extra starting manpower. In my opinion early game balance is more about timing issues than raw unit stats.
And volks to lose their capacity to build sandbag, or to have it behind T1 or T2 or vet1 but no more like it is today.