That's the problem: you want SIMPLE. CoH2 isn't simple. Brits already have it simple. If you want to defend, park a section behind heavy cover and you will win every engagement. Just watch for grenades. Ostheer is a defensive faction yet anything better than some cons can afford to charge grens in heavy cover and win. And sometimes even cons win. So u need an mg to help. 500mp to fight off 240-300mp unit. Do you hear anyone complaining? Factions have unique strengths and weaknesses. If defending is easy, attacking should be harder. Period. U want a mortar? Build one AND ACTUALLY GIVE A DAMN DEFENDING IT WHEN ITS BEING ATTACKED INSTEAD OF HITTING BRACE.
Basically all of this is completly wrong. FeelsBadMan
Brits dont autowin behind heavy cover beacause of grenades. They are either getting killed or have to move. Moving= losing infantry fights because Brits have the worst moving accuracy in COH2 plus are bad out of cover. Volks lava nades denies them cover/garrison and then Volks can beat them unless Section has double Bren + 5 man upgrade (so basically only late-game). G43 Grens eat them alive too because they dont lose much DPS closing in. Infantry sections scale very well and are very good if you can manage to double equip them and buy the 5 men upgrade but they aren´t good early game at all because STGs and LMG42s or G43s come earlier than their weapon upgrade and bolster. Plus UKF players typically don´t tech nades until they have a tank out so that´s another big drawback of infantry sections.
Grenadiers cant be charged by any mainline infantry apart from PPSH cons with urra. They will flat out win vs Riflemen, normal Cons and Sections if they can just sit in cover and wait for enemy to get to them. If you don´t believe me I can just show you in cheat mode. You completly underestimate Grenadiers. They are great and super cost effective if played right.
Mortar pit is super hard to defend at the moment. Even top players fail to protect their mortar pits. It´s not a L2P issue. Plus mortar pit is only effective in a specific area, which is a huge drawback. They are just not good at the moment. If you don´t believe it just play UKF and build mortar pits. See how well it goes. From my experience playing 2v2 they are a failure in 90% of cases. No matter if I build them, opponent builds them or my teammate.