I think its kinda sad that 5+ engineers can be as strong as 20+ t1 tanks/some t2 tanks. so you can just have some engies reclaiming/assisting and when some enmy units come your engies throw up 1-5 t1 pds and are able to either win or delay the enemies approach long enough that your army can smash them (the odd 1-3 t1 arties in the enemy army just can't kill the pdspam fast enough in many cases :/ ), also a new t3 mex with 20+ engies around it can hold of some quite strong amount of t2 or even some t3.
Also breaking through the enemie lines and attacking an heavily assisted HQ/factory/mex/whatever isnt worth it.
This can make attacking quite frustrating and lead to somewhat static gameplay (ofc a matter of preference).
I think it would be nice if heavy assist (5+ engies or whatsoever) on (t1 pds or rather defense structures in general) e.g.:
1 engie 5bp; 2gies 9,5 bp; 3 engies 13 bp; 4 engies 16 bp; 5 engies 18,5 bp; 6 engies 20,5 bp; 7 engies 22 bp etc.
with like a minimun bp for a lot of engies (so if you got 50+ engies adding 1 engie to the project would mean +1,5 pb or sth)
this would also give a possiblity for some more faction diversity like UEF having a cap at 3-2,5 bp and cybran one of 1,5-1 bp.(and sparkies suffering no penlties whatsoever)
same ofc for all