If you don't have any cav modifiers I would honestly cut it if your having any money problems.
Cannons slowly get better as the game goes on so they're not very cost effecient when you first get them in tech 7, you can get one to speed up sieges but don't expect it to effect combat to much.
If I remember correctly tech 16 is when you wanna start making sure that your running a full backrow of cannons with every army. This will also give you a big advantage over the AI, because I usually see them only have around 10 cannons per stack still. If you're up against a big neighbor Ottomans, PLC, Spain, pay attention to their stacks, you can probably win fights even if slightly out numbered e.g. 40k vs 50k with a better general or defensive terrain on your side.
Also as the game goes on having a full front and back row on a single tile will almost always cause attrition. So creating armies that are half of the fighting force becomes the better method. For example, combat width is 37. So I'll make a "40 width" template with 20 int 20 art. I'll make two armies with this template, and if I see a big enemy stack these two armies will join up before the fight to fill the full width.
Very late game, age of revolutions, I tend to also make stacks only for sieging 40 art stacks, along with stacks of pure infantry maybe like 30k. In most battles, even that you win you'll still take heavy losses to the infantry with none to art. So the couple extra 30k stacks are so you can fill your front row before the next battle while the other stack reinforces in friendly territory, according to the wiki you reinforce at 100% in your own provinces and 50% in enemy/allied.
I personally don't usually use cav mostly cause I don't like to micro it. In every fight infantry will always take more casualties than cav. IMO it's just easier to always keep the infantry healthy, then juggle cav around also, or be in weird situations where I have to take some cav out of an army because I screwed up the ratio's after multiple battles.