How many leagues and tournaments do you bowl?
How many bowling balls in you current arsenal? 
How many balls do you take to league or a tournament?
Do you prefer multiple layouts in the same ball, same layout in different balls or different layouts in different balls?

I bowl regular 1 night a week and a roster sub another night.
I have roughly 15 bowling balls.  Arsenal depends on conditions.
I usually take 4 balls to league with me; 3 and a spare ball.
I usually take 6 balls to a tournament; 5 and a spare ball.
I prefer similar layouts in multiple balls with one "specialty" ball (2 inch pin).

3 leagues and around 7 tournaments
I have too many balls...15.
5 to league (lanes are never consistent week to week).  9 to tournaments
Different layouts across different ball.

How many leagues and tournaments do you bowl?
How many bowling balls in you current arsenal? 
How many balls do you take to league or a tournament?
Do you prefer multiple layouts in the same ball, same layout in different balls or different layouts in different balls?

Taking the year off this year, but if I were bowling...

2 to 3 leagues; 6 to 12 tourneys per year.
Down to 14 (and still going down)
3 balls for league and 4 to 5 for tourneys.
I had two hyroads and two Naturals with different layouts. Also use diff layouts with different balls.

Sunday League/ full time sub Wednesday nights, try for 5-10 tournaments per year

Total arsenal: 5 balls
Sundays: take 3
Wednesdays take 4
Tournaments: all 5

Different layouts and surfaces. Crossroad and Twisted Fury drilled similarly but different surfaces, Crossroad is 4000 abralon to read lanes and Twisted Fury has polish to combat early hook

1. Three leagues: One wet house-med-hevy to medium; One medium-to light oil house; and one dry to toasty house. And about 4-5 tournaments
2. Eight to nine balls in my current league arsenal, though I have many more to choose from.
3. Because the leagues I bowl in are inconsistent, I take 6 every week. It's been years since I've done this, but this year I have to.
4. To tournaments, especially those I've never bowled before, 9-10 balls.
5. This is an intriguing question, that I didn't even realize until I thought about it:All three of the options you mention......I use.
I have multiple layouts in the same ball that I use on dry conditions, to give me the ability to play "around" someone who is using the same line as me, when oil is at a premium.

How many leagues and tournaments do you bowl?
How many bowling balls in you current arsenal? 
How many balls do you take to league or a tournament?
Do you prefer multiple layouts in the same ball, same layout in different balls or different layouts in different balls?

1 league a week, 4 tournaments a year.
I have 20-25 drilled and 30 undrilled
I take 5 to league and 5 to local tournaments and 8 to out of state tournaments.

I have 3-4 layouts I use consistantly. I see many benefits when having the same layout on a few different balls and using a few different layouts on the same ball. Have done both.

2 Leagues plus subbing.
Probably 20 tournaments.
Total 12 balls
6 to league and tournament, because I am too lazy to change bags.
Similar layouts but different sanding to get the reaction I want