What are the strategic management theories? How many theories and approaches are there in the management literature? How many theories of management/strategies a do manager learn?
This is not a black or white (yes or no) question. It is really a question of cognitive ability and an organisational-climate that encourages the use of strategic thought. (see link)
How to assess strategic management? There are several scales below.
As per the other questions you mentioned, the following articles will help you find more specific answers:
Assessments of Strategic-thinking-Individual level
Brønn, P. S., & Olson, E. L. (1999). Mapping the strategic thinking of public relations managers in a crisis situation: An illustrative example using conjoint analysis. Public Relations Review, 25(3), 351-368.
Dragoni, L., Oh, I. S., Vankatwyk, P., & Tesluk, P. E. (2011). Developing executive leaders: The relative contribution of cognitive ability, personality, and the accumulation of work experience in predicting strategic thinking competency. Personnel Psychology, 64(4), 829-864.
Measures of Strategic-Orientation at the Organisational level
Strategic types scale
Conant, J. S., Mokwa, M. P., & Varadarajan, P. R. (1990). Strategic types, distinctive marketing competencies and organizational performance: a multiple measures‐based study. Strategic management journal, 11(5), 365-383.
Miles and Snow's typology of strategic orientations
Shortell, S. M., & Zajac, E. J. (1990). Perceptual and archival measures of Miles and Snow's strategic types: A comprehensive assessment of reliability and validity. Academy of management Journal, 33(4), 817-832.
Strategic Orientation of Business Enterprises (STROBE)
Venkatraman, N. (1989). Strategic orientation of business enterprises: The construct, dimensionality, and measurement. Management science, 35(8), 942-962.
Theory & Strategy
Game Theory
Camerer, C. F. (2003). Behavioural studies of strategic thinking in games. Trends in cognitive sciences, 7(5), 225-231.
The Resource Based View
Peteraf, M. A. (1993). The cornerstones of competitive advantage: a resource‐based view. Strategic management journal, 14(3), 179-191.
Wernerfelt, B. (1995). The resource-based view of the firm: ten years after. Strategic management journal, 16, 171-171.
I don't think all managers are strategic. Many managers are so absorbed by the daily work that they never find the time to reflect strategically. Strategic analysis requires appropriate work organization.
Regarding strategic theories, there are several strategic theories and models, mainly LCAG (or SWOT) model, BCG matrix I and II, ADL matrix, Mckinsey matrix, Porter's five forces model, generic strategies of M. Porter, Resource Based View (RBV), Core Competencies theory and strategic intent theory (Hamel & Prahalad), Dynamic capabilities theory (Teece et al.),...
There are certainly other theories. I Hope I have cited the most known and interesting ones.
Very interesting answer as posted by my friends Daryn and Zouaoi. I want more clarity by furthering the more discussion on strategies and strategic managers. I want know more with exact theories on the appropriate situation of applicability of theories and research. I welcome more inputs on the theme.