PGI can easily set unmarked tiers in the skill tree based on gains and points spent to balance it out with other trees. This can work and it won't matter how many or how few points you have in the skill system.
This means that getting 25% of the agility bonuses will cost (x) points, getting the next 50% of it will cost (x+y) points and getting the last 50% for 100% effectiveness will cost (x+y+z) points.
Now getting (x) points should have equivalent value among all the available skills that you can get with (x) points and the same should go with (x+y) and so on. This doesn't have to be exactly equal, but relatively close enough to make it a choice for some players.
A good choice does not mean that the player-base is split 50-50 between a certain path on a tree. You can have it 80-20 and it can still be a good choice to make.
The problem with these mixed nodes is that it messes up and dilutes the values of the points spent to get something. Separation in the tree is also necessary (at least for the initial design) to see how far a player is willing to go to get something before picking off items in another branch. This does not mean that it is impossible to value the current tree as it is, but it just puts more factors in that you have to balance out. A question to ask yourself is,
"Is spending 22 points in survival returning an equal value when I spend it on mobility or weapons?" If not, then the separate trees are not equal and should be re-evaluated or further categorized into tiers of superior and inferior trees which just makes the whole thing more complicated to balance out.
A simple way would be to break the 91 points down into 10 point segments with an 11th point spent down one path being exceptional compared to the rest while getting 10 points normalizes your mech in some way (just as an example). Meaning the more 11 point goodies you pick up down branches means you will be more deficient in other aspects.
A tree should have a default setting that is considered the balanced setting and this would be your baseline battlemech and picking more 11 point items will reduce your effectiveness in one area or other.
Numbers can change, of course. Can be 5-6 or 20-21 or whatever, but PGI should also set their tree and tell (at least themselves) that
"This is the default tree setting for all mechs" and adjust changes from there.
Edited by Elizander, 03 March 2017 - 10:16 PM.